A/C - heater blower motor

Hey guys,

My car: '94 S-10 Blazer, 4.3 L V6 engine, 2WD, 4Dr

My problem: I am pretty sure that the fan on my air-conditioning/heater is on its last legs. Some days it won't even work, but most times it'll start out at normal speeds and then gradually decrease in speed with an increasing humming noise. So my question is, how difficult is it to replace the fan motor, and do any of you know of any good articles that walk you through replacing a fan motor? I've heard rumors that working on your A/C system is very risky since it's all sealed and pressurized, but I wasn't sure if the fan motor is contained within that system or if it is separate.

Thanks for any info you can give.

Just changed the blower motor in my 99 LS. Took about a hour and a half of work. Slicing through the casing with a knife was a bit scary, was afraid of hitting somthing mostly. Other then that, very simple install. Followed my Haynes book and now no more humming noises.

Just replaced the blower motor on my sons 94. Motor is on passenger side inside engine compartment. No big deal, 1/2 hour. Hardest bolt is one underneath. You will have to move your coolant jug out of the way----makes it a little easier.