Just fixed this problem on my 196k mile 01 tahoe, dirty throttle body. ther are 3 nuts that bolt it to the intake manifold, and are 10mm. Once the air intake tubing is out of the way you can remove the throttle body by removing these 3 nuts, pull it off of the studs, but leave the 2 bottom rubber lines connected. these are EGR coolant lines and will spew antifreeze everywhere if you take them off. The vacuum line up top can be removed, as well as teh electrical connectors. Lay some towels underneath, goto walmart and get a couple cans of the supertech carb cleaner (1.19 a can) and hose that bitch down!. spray it and rub all the black **** off with your fingers. there are a couple holes in it you want to spray out, which would be the idle air bypass system. prop the throttle body open with your fingers while spray, spray it inside and out. ITs very easy but....no offense, it doesnt sound like you are very mechanically inclined at all, so you may ask some friends who actually are, to help you. Literally the only tools you need are a 10mm socket, and a flathead screwdriver to remove the intake tubing.
My truck runs like new, no more low idle when backing up, no more dying when turning around, etc.