3A engine timing belt change

[Al Streicher]

I am planning ahead to replace my timing belt. It looks pretty easy, similar
to my Isuzu diesel.
I know how to loosen the PS pump and the alternator, so I can remove and
replace those drive belts.
My question is about the AC compressor. Is the drive belt loosened by the
process of removing the pulleys, shims and half pulley pieces attached to
the crank, or do I need to loosen some bolts on the compressor itself?

Also is there a tool to lock the cam in place?

This is a 1990 80 4cyl 2.0.

Any pictures or BTDT's would be appreciated.

Thanks,
Al Streicher
Mililani, HI.