Heater Core Advice?

I am about to replace the heater core in my '96 XJ (with AC). I have the heater core and am ready to begin, but have 3 questions before I dig in.

1) How to I safely discharge the refrigerant in my AC system? Do I just go to a local repair shop and pay what they charge are are there cheaper and ethical options (I'm in WA).

2) Are there seals in the AC system that I will need to repalce before putting it back together?

3) What else should I replace while I'm in there? Blower motor? Evaporator?

1. Cheaper AND ethical options? No. It shouldn't cost too much though to just have the system evacuated.

2. You should replace the drier, and if you can find the o-rings for the other fittings you're taking apart it wouldn't hurt to replace them as well.

3. Definitely the evaporator.