Can you make Peace once at war with a Faction?

So I’m currently best friends with two factions but at war with the third. How do i stop the war status? Cause I got all the tech from the friendly one. After i clear the crab lairs the hate still like 75% how do you make peace?

Phoenixpedia says you can’t raise relations from war.
So I guess you just raid them as they get new tech, but leave them untouched otherwise? Can’t research anything if they are dead after all.