I'm having problems with the AC Compressor, Power Windows, and a leak.

What is your question?

I love this car, it drives great and is decent at the pump, but there are some problems. When it rains water leaks in and pools on the driver side floor, none of the windows roll down, and now a mechanic says we need to replace the AC Compressor. I inherited this car from my father and he says that he's not willing to pay the $600 to fix the AC Compressor because of all the problems he fixed before I owned the car, plus the leak means that the problem could arise again. Does anyone know how to fix that leak, the windows and could I fix that compressor myself?