I'm not the stupidest man in the world, but I forgot how to do it exactly on my 2001 S10. It's a 4cyl. and I just don't know where the belt tensioner is so I can remove the air compressor, thanks!

IF this is a 134" four cylinder (2.2L) there is no reason to remove any belts or compressors to change spark plugs. The front plug can be accessed simply by moving the AC and heater hoses out of the way enough to make room for a 3" extension, ratchet, and socket. The rest of the spark plugs are a relatively straightforward R&R. If the hoses are difficult, you can remove the single bolt holding the hose support clip to the thermostat housing.