The Romulan Republic wrote:The war with the Empire going on for ages is repetitive and it doesn't fit the optimistic tone of the ending of Return of the Jedi.
I'd rather the films focus on another idea from the EU: that the Empire broke into a bunch of independent factions. And because there's no way the Rebellion would be able to quickly take control of everything, there would still be conflicts. But it would be a bunch of little wars rather than one big one. This allows subsequent stories to have a diverse group of villains and conflicts.
You can quite easily justify a demise of the Empire as quickly as you like by saying the Imperial Senate, implied to be not entirely on board with the oppression in the original films, defied the order to disband and assembled once more and the military - Really, how much does Admiral Piett say, in the films, seem to actually like the oppressive bullshit? Tarkin's an asshole, sure, but say Admiral Motti and Ozzel and General Veers are depicted as largely professionals - accepted their legitimacy in lieu of any actual succession as Emperor.
The Emperor's manipulation of the Clone Wars comes to public attention. Galactic Republic restored. Amnesty for the Alliance to Restore the Republic. Republic Admiral Ackbar, Supreme Chancellor Mon Mothma. Excecutor-class command ships with red stripes.
If say 90% of the Imperial Military accepts the Imperial Senate as its legitimate governing authority, then the actual crazies would be dealt with in short order.
Total time taken; a few months.
If you're not following the EU, you don't have to have the EU notion that all the Imperial forces's officer class are asstards from noble lineage who really like stamping on people's faces. Certainly it is hard to imagine say Veers, Ozzel or Tagge as crazed warlords fighting for their own personal egos, even if it is very easy to imagine Tarkin doing so.
You could even explain all that in the opening crawl and then set your film in the Restored Republic.