How do i put fanbelt back on a 1988 cadillac Deville I can get belt over the hump

There is a tension pully that you need tocompress in order for your belt to go ovetr the pulley there are no adjustment bolts for the belt it is done all by the tension pulley it is the pulley that has a 1/2square so that you can put a 1/2 ratchet or breaker bar on and decompress with this will solve all your belt problem