According to the Merc manual and every other book I have, this is not supposed to be difficult, but the Gen 6 (6 bolt) cover has a channel around the bottom that goes over the oil pan and a post sticking out from the block gasket surface on either side about 1/3 of the way up that the cover fits over. Problem is, the posts prevent the cover from pulling straight up and off the oil pan, so you have to pry the top of the cover away far enough to clear the posts. I actually ended up breaking off a small corner from either end of the top of the channel on both covers I removed (managed to recover the pieces). I've tried positioning them to see how they'll go back on and it seem like it's gonna be hard to remount them. Any suggestions? Also, the rubber gasket on the oil pan still looks good- any reason to cut it off and use the replacement one that came with the new cover o-rings?

They are made to go on before the oil pan. Its a pain to get them back on. Loosen about 5 oil pan bolts on each side of the front of the oil pan to make it easier.

That's kinda what I thought I'd have to do. Thanks-