Oil pan gaskets and seals dilemna

I am in the process of installing new cork side gaskets and rubber end seals in my LA 360. I have a couple questions. I notice that the cork gaskets protrude past the point where front and rear seals sit. Do they need to be trimmed to fit.? If not which end should overlap/underlap ...Front seal or rear main seal. Also the "nibs" or "nipples" on the front seal seem impossible to get thru the holes in the pan. Any secrets on how to do this eg. enlarge holes slightly or?....?