There are likely four ways the governmental system can change: Buildup, Breakdown, From Within, and From Without.
Buildup is the creation of a new system from scratch. Seasteading is an example.
Breakdown is what can occur before buildup. It is the violent refusal to be a part of an existing system, and is often a result of war.
From Within refers to changing the system by using its own laws to decrease the power it holds.
From Without means changing the minds of the masses so the very legitimacy of the system is called into question.