First implement a food and medication embargo on a country.
Famines and epidemics follow.
The population grows restless and wonders if changing leadership would make all its problems go away.
Meanwhile, encourage migration to the West of a diaspora which is promised to be the ones to take over if they assist in taking down the government.
Foment rebellion and demonstrations through the patient, termite-like work of NGOs : leech on legitimate concerns of the population, provide training, tools and comms to radical groups, and turn up the heat on the demonstrations to the point they become violent and the government is now facing riots and has to send in anti-riot police.
Have all Western mainstream media and chancelleries speak of "police brutality", even if there hasn't been any.
Speak of "blood-thirsty regime", and challenge its legitimacy to stay in power.
Have the Western audience basically say " I support the regime change because I love the people of that country, I juat hate their government".
This is what China, Iran, North Korea, Cuba, Venezuela, etc. have been facing, some of them for decades !!
Welcome to the EU, where dissent is brutally crushed. Swiss Colonel Jacques Baud used to do intelligence analysis with NATO, but he has reached unacceptable conclusions about the war in Ukraine. Therefore, he has been sanctioned by the EU and cannot access banks, cannot buy food etc.