If you are mechanically inclined, it's do able. Biggest thing is to get the bolt off the crank pulley, remove the passenger engine mount, and when you get the new belt on, turn the engine SEVERAL times with a ratchet before you lock the idler pulley in place.
You'll also be pulling the spark plugs, the serpentine belt, and the passenger tire. In addition to making 100% sure the timing marks are lined up perfectly. You'll even have to make your own timing mark on the crankshaft if the belt hasn't been replaced before. To get the crank pulley off, you'll probably need a air tools in addition to the prybar locked into the flywheel.
Or, you could take it to a good technician and drink some cold beers while he busts knuckles and asks for forgiveness for the profanity!