If I was magically put in charge of it at the time and I had the option to undo my influence on the film I'd make radical changes. Han dies, Leia uses force powers in the end battle with Vader, Emperor, and Luke, stuff like that. Some things I'd throw in there just to see if it'd go well with the audience. Throw in some dissension over Leia still holding the royalty title after the planet blew up from the other rebels. Bye bye Ewoks, hello alternate but still feasible alien race. Also throw out any love drama beyond Leia seeing Han die and the ramifications of that.
If it turns out bad revert to the original timeline. Also if it turns out good still return to original timeline but wait for a while.

If I was magically put in charge but with no option to undo what I've done. Also with zero option to back out I'd have to direct the film 'cause magic. I'd probably try to make it as similar as possible to what I remember as the original. Admittedly that'd be tough as Jedi is my least viewed Star Wars film. Still I'd try my best. Good thing is that I barely ever watched the SE of Jedi so it's practically guaranteed not to influence the production. I don't know, I just wouldn't want to permanently erase the original story from the timeline. Given what this site is and everything, it wouldn't feel right.