1996 Cadillac Deville belt tensioner remove and replace

Access is a bit tight, the tensioner is actuated by a 1/2 inch square drive. A 1/2 inch breaker bar, or belt tensioner tool works, a 1/2 inch ratchet may be a bit thick. The bolt holding the tensioner to the block is 13mm, and a ratchect with shallow socket may work. You can also loosen the engine mount and trans mount bolts and lift the engine a bit to gain some room. Caution when lifting on the pan though, it is aluminum.