what tools do i need to change an alternator and serpentine belt 2001 pontiac grand am 2.4

Hello, it's seriously hard to coach this because you really need to be prepared for whatever comes your way. I'd say a standard set of mechanics tools, including socket wrenches, open and closed end wrenches, screwdrivers, pliers, larger breaker bars, possibly hex and torx wrenches and sockets... I'd recommend obtaining a workshop manual first to familiarize yourself with any repair before trying to undertake one.