Well...the people need to stop paying their taxes and start fighting back.

Plenty of things you can build effective bombs with using run of the mill supplies. Use Guerilla warfare-- bomb their barracks, burn their HQs, run up -- douse them with gasoline and set them on fire before heading back into the hills.

If they can -- get some 3D printers and begin printing guns (easy to get the plans online).

There are more citizens than there are military -- should be a relatively quick job to eliminate them completely, crush their spirit, and terrify them using terrorism tactics.

Attack them at night, do run-and-guns, make them scared that around any corner lurkes someone ready to slit their throat.

The military there is unorganized, underfunded, poorly trained, and used to compliance. Stop complying and these psychopaths won't understand what to do -- they'll cannibalize each other and give up once they realize people won't just act as benign target practice for them anymore.

The question is, who are they going to setup after that.

Hopefully a limited Government society.