So we have three remaining representatives in the CL. All three should make up the premier league top three, with a worst case scenario being Chelsea slipping to fourth. So Champions League winner should really not matter. Top four get the CL spots.
West Ham could win the Europa, although I suspect that complication dies tonight. If they did, that would go into the one extra spot.
FA Cup winner and 5th get Europa. Plus Leicester get an extra Europa if they win the conference league. So ideally we want one of the top four winning the FA Cup. Then its back to 5th and 6th for Europa. Next available league space automatically will get the Conference slot as Liverpool won the League Cup.