they literally wrote the script like this:
Finn confirmed Force Sensitive and Kylo stronger with the darkside of the force
No Death star that can wipe out galaxies that's just overkill
More of a focus on Kylo and his Knights tearing shyt up than this First Order suddenly springing up and conquering the whole damn universe like people wouldn't try and stop them before that
Rey a little more nerfed and no Finn drinking snot water
Lupita as herself with make-up and not a damn cgi character such a waste
Make a Finn a super soldier who is trained to kill Jedi who once he turns good still had nightmares of the atrocities he's committed. Thus he spends the rest of the franchise trying to atone for his sins
This way you can have Rey as the pure spirit who brings out his goodness.
Also you could keep the Starkiller base. Except this time the big twist is it's a trap. It's whole purpose is to lure the Republic forces (nix that resistance crap) only to blow up the planet destroying most of the Republic forces
Also make the First Order it's own thing with own identity rather than an empire knockoff. Like Communists vs Fascists.