You may get a Soviet Union's relatively peaceful breakup if you follow Soviet Union's relatively gradual transition from power. It's not a given, even the Soviets had their 1991 coup attempt.

Also, it's not like Soviet Union's breakup didn't leave any problems. Post-breakup Russia has a track record of military conflicts - Chechnya, Georgia, Ukraine. Post-breakup Belarus fell back to dictatorship.

I don't think we have a reliable recipe for low-harm transitioning away from authoritarian regimes.