Theyre not hard to replace but you are going to need a wrench to retract the belt tensioner. There is a diagram usually under your hood for the belt route. but the tensioner pulls back off the the belt so there is slack on the belt so you can pull out the old one and slip in the new one being sure to follow the same route as the old one. The only problem is your going to have to get yourself a wrench to do this.
heres a pic of one
http://www.amazon.com/Summit-SUM-900035-Does anyone know how to change an Alternator belt for a 1998 Rav4?
It requires a serpentine belt tool. first take note of the routing of the belt, raise the car up and remove the shield covering the crank pulley, put a 19mm socket on the tool, find the tensioner toward the top of the engine, put the tool on the fixed tensioner casting (its a 19mm hex cast right into the tensioner) (do this from the bottom) and pull down. this will take the tension off the belt and allow you to slip the belt off the waterpump pulley. let the bar go back up and the whole belt will fall off. replacing is reverse, its tricky the first time......even the second or third. good luck! oh and dont try to drive it to the repair shop if you cant get it back on.....the waterpump wont be working so you'll risk engine damage by overheating, the power steering wont work, the battery wont charge, and as if it matters...the A/C wont work either!
