use influence to keep Lothern at peace with all the other factions.Declare war on Lothern to weaken it, the use gifts and influence to raise your relationship.From here, you need to click on the flag of a specific country to pull up their unique diplomacy screen. All you have to do is click on the hand-shaking icon to bring up your diplomacy screen. Leaving a faction as a member is relatively simple.
If you already researched the ability, go to the diplomacy page (type ‘e’ on the country you want to create a faction with).