I would've opened it with Luke thinking that Leia would always love Han, so Luke goes back to his roots on Tatooine and hooks up with his Academy sweetheart. She's now a single mum of a cute kid that says "Yippee" alot (It's like music) and he acts as a surrogate father and takes them both on picnics to beggar's canyon. He also finds time to rescue some workers from a burning spice refinery (The refinery was experimenting with a deadly form of toxic spice!).
Meanwhile Leia goes off to rescue Han but we don't see her for the rest of the movie. Instead we follow Lando who has got a low paid job in the Emperor's palace. One day, Lando uses his scoundrely ways to hack into Palpatine's computer and increase his wage packet.
Palpatine and Vader catch him but before the Dark Lord can force choke Lando, Palpatine yells "Stop Lord Vader... he has done well". Palpatine realises that Lando has the skills to build a new Death Star and Lando just happens to have some sketches for one that he scribbled on the back of some Sabacc cards.
Palpatine, sensing that Luke could still "Be a threat to us", sends Lando to swap Luke's new green Lightsaber crystal with an evil red one. The first time Luke ignites his red saber he falls under the power of the Dark side. This manifests itself by his clothes getting all dirty and him not shaving.
On the otherside of the galaxy the Death Star II is complete but Lando has designed it too well and so it becomes sentient (Like frickin' Skynet) and turns it's own laser on the Imperial Fleet. It then kills Palpatine and Vader and lays in a course of Courscant, bent on destruction!
Luckily back on Tatooine, Luke happens to fall into a garbage masher at Watto's junkyard (It's like music) and just before dying, Ben's ghost visits him. Luke stops being evil, busts out with his saber that has magically turned green again and heads off to stop the Death Star (Some pitdroids cheer as his X-Wing takes off).
Luke's X-Wing arrives at the Death Star II and heads straight for the thermal exhaust port (That he knows all Death Stars must have by law). Secretly he has loaded some of the deadly toxic spice into a proton torpedo and fires it into the death star's main reactor. As the evil space station is melting and dying Luke rescues Lando (Apparently Lando is forgiven all the evil stuff he's done because he's lovable Lando).
Luke lands back on Bespin and Lando waves him goodbye. Luke then uses his force power to super compress some Tibana Gas into a Japor Snippet necklace (It's like music) which he gives to his Academy sweetheart in the final scene back on Tatooine. Just as this is happening Leia and Han get back from Jabba's palace. Luke's new fiancee shows off the beautiful necklace to Leia who looks obviously crushed. In turn Han sees Leia's reaction and realises she loved Luke all along. He utters the words "I won't get in the way" and walks off into the desert.
As the suns set on Tatooine everyone has a party/parade at Jabba's palace with dancing Jawa's singing "Yub nub". Luke symbolicly hands Jabba a glowing white electric globe that is never explained in any way and Jabba holds it aloft and shouts "Peace!" in Huttese and we iris in on the credits (It's like music).