The water pump on a lemans is ran by the timing belt. The pump is not like a conventional water pump being that the housing is actually cast into the block the pump itself is just an insert that goes into the block. You have to take loose 3 Allen head screws and pull the pump from the housing there should be an o-ring on the back your new pump should have one. Put all of it back in reset the timing and replace the timing belt remember the water pump drive sets the tension on the timing belt so put tension on the gear and tighten the Allen screws and you're done