just find the right socket size. if your car has a tensioner, you get a wrench and use it to push the tensioner away from the belt to relieve the tension while someone takes the belt off.
if you don't have a tensioner, you unbolt the alternator to relieve tension then replace the belt and use a screwdriver as a lever to pull the alternator so the belt is tight and bolt up the alternator.
all you really need is a socket wrench and a combination wrench