How to build a long-term campaign is a difficult challenge. Bureaucracies by their nature have the long-term commitment of workers, especially the elites. It is far easier to go along with the prevailing way of doing things rather than constantly pushing for change. A key to change is legitimacy. If citizens withdraw support, even the most oppressive regime will collapse.
Bureaucracies are similarly vulnerable.
But just saying 'withdraw support' is inadequate. The question is how. Challengers need to understand, through analysis or experience, how the bureaucracy maintains loyalty, how communication systems operate, how links are made with other organisations, how power is exercised against dissent, how people's beliefs and commitments are forged. Furthermore, just understanding how the system operates is not enough. It's necessary to know what actions will bring about change.