ouch man
this sucks, i just got done doing this myself, you cant take off the oil pan because the cars frame that is welded on is in the way so you have to take out the entire engine, its about 600$ in shop or go buy your own tools like me and it was about 300$ plus i learned from it and got experience, but the reason my oil pump went was because somehow the oilpan gasket got decinagrated and sucked in by the pump and the pumps screen got plugged
this happened in a 92 mustang lx hatchback 2.3