Sorry for the delay, the reasons behind it were a little...complex.
(Well, strictly speaking they were a combination of laziness and absent-mindedness, but working out the exact formula of how the two mixed together is quite, quite complex.)
So when we last left our alternate version of the Star Wars sextet, we'd left it pretty much like the classics you remember, with just a minor difference. Luke already has confirmed with Yoda that Vader is his father, but on the whole, Han is still frozen in carbonite, stolen by Jabba the Hutt, and headed for Tatooine, while Luke recuperates from impromptu surgery at the hands of his own father. We open with Luke getting ready to return to action and join Lando and Chewie in the hunt for Han, when he and Leia receive news from the Rebel leader of a major offensive--in fact, it might just be the end of the Empire. The secret clone factories of the Emperor have finally been located.
(This, by the way, is the reason for the emphasis on the "undisclosed" location of the final battle against the clonemasters of Mandalor in Episode Three. Despite the fact that I have a certain fondness for the Emperor's plan in 'Return'--"My ultimate weapon has been destroyed, due to a tiny, fatal flaw that I overlooked when creating it! You know what? Rather than just abandon that plan, I'm going to do it all over again, only this time without the fatal flaw..." I would, in fact, go with something different. And let's face it, the stormtroopers really are the big advantage the Empire has over the Rebels. Seemingly endless numbers of troops indoctrinated to be loyal unto death to the Emperor? Yeah, that's something you want to take out.)
The ground defenses of the factories are formidable, simply due to the sheer number of troops the Empire is cranking out--but the space defenses are light, since the stormtroopers are ground-pounders and the Emperor doesn't want to station a ton of troops there (due to the need for secrecy.) He instead relies on a deflection shield generated from a nearby forest moon. A sufficiently concentrated Rebel assault could smash the clone factories, and with the Mandalorians exterminated years ago, it's anyone's guess whether he could even repair them. Either way, it would be a major blow to the Empire if the Rebels could succeed. Best of all, the Emperor frequently journeys to the cloneworld, since it's the most secure location in the galaxy apart from the Imperial Palace.
But Luke and Leia want to rescue their friend. Mon Mothma, in a touching scene, lets them go--after all, one ship more or less won't mean much at the battle, but it will make all the difference in saving Han Solo. They head off to Tatooine to rescue Han.
When they get there, they find that Jabba's palace is surprisingly lightly defended--he has his Gamorrean guards, and Boba Fett, but his hordes of mercenaries and bounty hunters have been all hired away. Even so, a good deal of strategy and subterfuge is needed to get into the palace (ie, most of the opening sequence of 'Jedi' would be cannibalized here, leading up to the Sarlacc sequence.) The key difference? Leia finds out, as Jabba's concubine, exactly where those mercenaries have gone--the Emperor has hired every gun he can find, creating a secret army whose movements won't show up when Rebel spies analyze Imperial troop movements. This secret army is lying in wait to ambush the Rebels--it's all part of a trap, you see, to crush the Rebel Alliance once and for all...
At that point, Luke springs his trap, capturing the skiff and duking it out with Jabba's guards. He and Boba Fett battle--the last of the Jedi against the last of the Mandalorians, a brutal coda to the Clone Wars, but Boba's lost a step over the years. In the end, he's just a little too slow to face a Jedi in his prime, and Luke dispatches him to the Sarlacc. (Note the lack of blind guys with sticks in this battle.) They destroy Jabba, rescue Han, and now are faced with the fact that they're the only ones who know the Rebels are heading into a trap...
Contacting the fleet at this point would be difficult at best--they've maneuvered into a secure position, and can only be contacted with a pinpoint-burst coded transmitter. Flying there would give them away, and the only people who have the proper coded transmitter are the commando team on the forest moon whose job it is to take out the shield generator...and needless to say, the Empire won't just let them through that shield to talk to their buddies on Endor, Han points out. Luke, though, has a plan.
A few hours later, the Millennium Falcon arrives at the forest moon of Endor. While the others hide in the smuggling compartments, Luke contacts the garrison on the forest moon. "This is Luke Skywalker," he says, "son of Darth Vader. I have come alone to speak with my father and the Emperor." Within moments, the shield dissolves and the ship is allowed to land.
From there, the two groups split up. Luke goes to the cloneworld, to meet with the Emperor. The others sneak out of the ship into the forest, to try to find the commando group. Instead, they run headlong into a group of cute, furry little aliens (I love the Ewoks. I'd make a slight redesign to them, so that they look more sinuous and otter-like, and less teddy-bear-esque, but the whole "cute" factor would remain...because that was what was so awesome about the Ewoks, that they looked cute and fuzzy and adorably sweet and nice and friendly...and then they turned out to be this vicious, savage, cannibalistic race of guerilla warriors who fearlessly charged stormtrooper detachments and beat them to death with heavy rocks. And then ate the corpses, probably.)
The cute aliens only look cute until they smile, revealing a mouth of needle-sharp teeth, and they quickly surround Han, Chewie, Leia, Lando, R2, and 3P0. They've made necklaces and decorations out of the remains of the commando group, and it looks pretty clear that they plan to do the same with Han and company...until C-3P0 begins to talk to them. He explains their story, the plight of the Empire and the Rebellion, describing the entire situation to the chief of the tribe, and swaying the Ewoks to their cause. (Yes, it's Threepio for the win, here.) The Ewoks agree to help. Han, of course, is a little skeptical of just how much help a few cute fuzzballs can be against a whole garrison of stormtroopers...until he sees the hordes and hordes of silent, vicious Ewok warriors, their siege engines, their cunningly designed traps, and their collection of empty stormtrooper helmets (not even stormtroopers venture into the forest at night on Endor.)
As Luke prepares to face the Emperor, he is met by Yoda and Ben. Or rather, their blue ghost bodies. Yoda has died. Luke is truly the last of the Jedi...but yet, there is another hope. Yoda never told Luke, but he has a sister. If he fails, she will be the last hope of the Jedi Knights. But only by letting go of his attachment to his father and destroying Vader can Luke survive this final trial. Luke refuses. Surely, the three of them together can redeem Vader? Yoda shakes his head sadly. They cannot go into the presence of the Emperor, lest he destroy them. Luke will truly be all alone.
And here we go. Luke battles Vader, with the Emperor and thousands of stormtroopers looking on. Han and the gang attack the shield generator, with an Ewok army backing them up. The Rebel Alliance, led by Wedge, fight an army of bounty hunters, mercenaries, and the scum of the galaxy. The shields come down, the factories get bombed, Luke redeems Vader, who dies stopping the Emperor as the bombs begin to rain down upon them. Luke barely escapes the carnage, the Rebels send the bounty hunters packing, everyone returns for a celebration on Endor where Luke lets Leia know that they're family, which neatly skirts the issue of who she's going to start dating. And with the Emperor lost and the clone factories destroyed, the Empire seems to be finally on the run.
(Until the endless parade of tie-in novels, that is...)