1991camaro_rs

hey guys sorry if this is the wrong place for this but, i have a 1996 trans am lt1 car, auto, and recently i noticed a creaking/grinding noise coming from the rear, pulled to my buddies shop and he said i have a rear stabilizer bar, that runs along the drive shaft that had a bolt loose and is rubbing on my rear, he was to busy to put it on a lift and i didnt have time to wait, he told me i could do it at home, one problem i dont know exactly which bolt it is, and i dont want to tighten it and make something, and adjust something wrong. anyone have or heard of this problem, thanks guys. this noise drives me nuts