I was going to put my new oil pump in (Melling high-volume) today, but I think I need to get a new pickup/screen for it?  The guy at the parts store said I could just use my old one, but there doesn't seem to be a good way to get it out of the old pump -- I'd be worried about damaging it.  I just checked - they're cheap so I might as well get a new one.  Is this the correct line of thinking or am I missing something?  The other benefit to using a new one is that I can make sure the clearance is exactly the same as it was on the old pump.  Seems like you'd want that to be pretty close....

You can twist the old one off. A little back/forth motion will get it out of the pump. To install, you can use an open end wrench that fits snug against the ridge of the tube, right where it fits into the pump, and tap it in. Be sure that it fits nice a snug. A lot of folks will braze the tube to the pump, but it's not really necessary for most applications.
A new pick up tube will be fine, if that's what ya wanna do...either way will work.

New pick ups are cheap enough too. I always stick a quick tack weld on em as insurance one the pan clearance if verified...