The 3 screws that hold the MAF on the throttle body are 7mm head screws.
Don't drop them....
Try a delco distributor or go to your local GM parts house (any division will do) and get a can of aerosol "Top Engine Clean".
That stuff will make your throttle body so happy it will blow your mind.
Spray a little on, let it soak, then spray some on a rag and wipe it off.
Hold the throttle open with your fingers and do the same on the back of the throttle plate and in the bore. Latex gloves are a good idea as the TEC might irritate your skin a bit.
If you are a bit squeemish, I can do it for you. Actually the stuff we use works pretty good at cleaning out the inside of the intake and the runners too. I don't know what we charge for it but it really helps.
I usually do a bit of extra cleaning on the Throttle body after the "induction service" that we do.
You can run the engine with the MAF off and spray the TEC in the IAC passage. It gets dirty too and can make the IAC a bit sticky in the bore at times.
The cans are big, don't spray it too fast, and you might have to take it out and give it the gas a bit, sometimes it will make the car smoke pretty good out the tailpipe for a few minutes. Your neighbors might call the fire department if you do it in the driveway.