TPM: Qui-Gon and Obi-Wan are combined into one character: Obi-Wan. OR (and?) make Anakin a young adult and the person whom he’s emotionally attached to is Uncle Owen, for a believable arc.
AotC: Have more Dooku background exposition.
RotS: Luke & Leia aren’t siblings.*
SW: Nothing.
ESB: Have Yoda not say anything about the other.*
RotJ: No DSII - instead, have the action that originally happens there be set in the imperial capital like it’d been planned, and the Endor part of the mission is the gang infiltrating the planet in a spy-like mission to disable some shields and whatnot and blow stuff from the inside-out. No sibling stuff.*
TFA: No SKB - have the film be about the search for Luke, in a race-against-time like fashion.
TLJ: Not sure.