I would have redone the entire trilogy. There would be no prequels or sequels If anyone wants to hear more of my ideas, don't hesitate. For ROTJ/VI:
There's no DS2. Instead we get the Eclipse or something which is under construction but is disguised as an incomplete framework for the battlestation.
Han wouldn't be rescued, he would have died due to a carbon freeze malfunction. Instead Leia and Crix Madine would retrieve his frozen corpse for proper burial as well as to take vengeance on Jabba and the Empire. Jabba and the Empire are baiting them under the pretense of forming an anti-Rebel union, figuring Leia would want to get back at them. Jabba's palace would be a part of the forest that was cleared and would have a lot of alien plants from its original location (not Tatooine here, more like Nar Shadda or Orvax IV) encircling it like a full-scale equivalent to a tacky island paradise photo.
Fett fights better, still dies after being thrown into the Sarlaac inside the palace, probably not due to a damaged jetpack. The Slave I might be used to fight like in Shadows of the Empire. Luke wouldn't resort to the elaborate plan he did in the real movie, they'd all probably try to infiltrate but Jabba's minions and the Imperials would be aware of it and try to capture them. The battle would spiral out of control and spill into the woods, but the Rebels' shuttle Tydirium leaves them to signal the okay before they can warn the fleet.
Emperor Palpatine isn't a Dark Sider, he's like in the original ANH story - a manipulated figurehead away on Coruscant. Darth Sidious (who probably would be known by his real name) is a separate person and not evil incarnate but well meaning, though otherwise basically the same. He rules behind the scenes. Part of his messing with Luke is that he encourages Luke to feel like he already fell to the Dark Side through his anger, despair, desire for revenge and impatience, but Sidious can help him become wiser, stronger, etc. There'd be a lot more carrot than stick in terms of how he'd get to convert him. He doesn't openly tell Luke to take his side near the end, he tries to use reverse psychology to get Luke to kill Vader out of spite, then capitalize on the catharsis of the moment to brainwash/influence him.
The Ewoks wouldn't be teddy bears so much as weird dark deer-puma-bear hybrids that would make the Empire's defeat a lot less embarrassing. Endor itself would be a lot more ominous, the sky would be turquoise or green and everything else would be much darker, even black.
Ackbar's cruiser is the one that takes the plunge, not the Executor. This damages the Eclipse to the point where the fighters can fly inside to destroy the reactor. The space battle would have the Imperial fleet tearing the shit out of the Rebels, but losing their Interdictors. Some of the ships would probably defect to the Rebellion. The Eclipse would be severely damaged but not destroyed by the end of the battle, orbiting amidst the cloud from the explosion.
Yoda appears as a ghost only. Instead of just talking to Vader, in V Sidious was pretending to be a friendly Jedi Master for Luke who was spying on the Empire partly to track down any Jedi who escaped the purge. This was done through being told by Obi Wan where he was so he could "help" as well as through tracking Luke's X-Wing's previous location when it reached Cloud City in case he went anywhere else ie with the Rebel fleet. He would encourage Luke to go save his friends in contrast to Obi-Wan and Yoda to make him fall into the trap and make him seem better to Luke. By VI Yoda would be killed during an Imperial invasion of Dagobah.
Leia would have some training from Luke to become a Jedi. She wouldn't be his sister.
She would have to struggle with the Dark Side too.
Sidious would open a channel between his tower, the space battle and the captured strike team seemingly to force a surrender or amnesty through threatening to kill the hostages and continuing to crush the Rebel fleet. This would just be done to inspire Luke to give into his anger, as he knows they would be killed by the Imperials anyway.
The ending would have celebrations but they would be only on Endor as they evacuated the Rebellion's strike team and maybe some of the Ewoks aboard what few ships remain. Then there would be an artistic shot at the end where dirt starts spiraling up into the sky, growing to the point where it morphs into the galaxy itself. Mon Mothma would reassure everyone that the death of Sidious will cause the Empire to fragment into warlordism and either form a government of genuine reconciliation or be soon defeated entirely.