A/C compressor Clutch, Help!

[Buenrostro_aldo]

My car is making a weird noise. It sounds like a ford when its out of power steering fluid! lol i hope some of you know what I mean.
Well a mechanic suggested that it might be the clutch to the ac compressor...
Does anyone have instructions on how to do it? Is it a hard job to do? Should I pay to have it done?
Thanks