Set up a provisional government made up of the people who made the coup possible and “negotiate” exclusive resources rights.

Pull a Norway and make a national sovereign fund from the resources.

Use the money from the resources to fund “national education systems” to make the next generation of people more like your native country.

Begin implementing laws that match my laws almost exactly.

After a couple years quietly begin a campaign to make the people of both nations believe the conquerored country wants to join my country.