Heather, there are several sized and different locations of freeze plugs on engine blocks and heads. Use a pressure tester to find the leaking one(s). After you find it, use a freeze plug tool to install new one(s). Punch the old one at it's weak spot(leak), then pull it out with vice grips. Not many diagrams available for freeze plugs, but there are plugs ont all sides of the block and front and rear of the heads.