Removing the alt is a straight forward job. However, the problem is space. First, disconnect the battery. After that, remove the accessory belts. Unplug / unbolt the wiring harness from the rear of the alt. After that, just unbolt the alt from its brackets and replace it with a new one.
Let me know if you run into trouble.
PS: If I recall, if you remove the inner fender liner on the passanger side, you may have more access. Make sure the vehicle is safely lifted and secured, remove the tire and there are plastic clips that hold it in place.