1/4" air ratchet is your friend for the cover bolts. and a 1/2" impact gets the crank center bolt (ya gotta take it off to get the crank gears off to get the oil pump off.)

as for the dent, you wont have issues with the oil pickup at the drain, the pickup is a few inches away. shouldnt be a big deal, but try to get it hammered out some when ya got the pan off.