Sorry for the delay in replying to your question. Wish I had seen it earlier. The alternator can be dropped out the bottom behind the cross member.
The most common problem is worn brushes. The assembly is less than ten bucks and can be replaced without removing the alternator from the engine. To verify they are the problem, use an ohm meter to measure between the two small terminals on the back. The little nuts might be rusty so use meter probes that are nice and sharp, and scratch the nuts a little to get a good connection. Also, little bits of carbon from the brushes often cause intermittent brush connections that can mimic worn brushes. This isn't an issue when the alternator is spinning but it can lead to a false diagnosis. If you find an open circuit between the two small terminals, which indicates worn brushes, tug on the serpentine belt a little to " irritate" them. If it still reads open circuit, the brushes are worn and the alternator will not produce any output.