Rules: Its a remake, so you can't change the story too much. It still needs to be recognizable as the same movie, (and throwing in a couple lightsabres while iconic isn't enough).
So what would you change or tweak to make it better? Keep in mind that most remakes are terrible. But lets have some fun.
(1) Naboo = Alderaan: We wanted to see new things in the prequels but we wanted to explore a world we were already somewhat familiar with, not a completely new planet we have no vested interest in. Here is why it would work, we know Alderaan is going to be destroyed if written correctly even knowing the outcome we can still desire to have it work out for the planet. Also, its much more heart wrenching in episode IV when we see this planet destroyed.
(2) Goofyness: While Star Wars has plenty of comical relief (and thats fine I love it) but Jar Jar's character was super annoying far beyond that of C3PO, or any other anecdotal character. Also the droid army was a little unbelievable as battle hardened when they have their 3 stooges moments and don't behave in an intelligent manner. Which leads into my 3rd point.
(3) The droid army: They needed to be cold, calculated, and look a little more menacing. IG-100 magnaguards (but an army of them) or even the commando droids from the cartoon show.
(4) Not such a strong difference or "pre-evolution" of ships. Walkers AT-AT, AT-ST, TIE fighters, Shuttle Tydirium, Star Destroyers, X-Wings
(5) No Samuel L. Jackson