Yea, the engine needs to come out.....or the entire k-member needs to come down.
Unless you are just changing the gasket...in which case, you can do it with the motor in the car, but you will need to unbolt the mounts and lift the motor up high enough to drop the pan low enough to snake out the old and snake in the new.
It sucks but I have replaced the gasket with the engine still in the car. I drained the oil, took the engine mounts loose and lifted the engine. Took all the oil pan bolts out and dropped it as low as I could. Scraping the old cork p.o.s. gasket out was the biggest pain. Didn't want any of that crap to fall into the pan. Fishing the new gasket around the oil pump pickup was a pain as well. It can be done, but you're gonna need a lot of patience.
Yep It is a PITA. This is a big reason why I want to get a tubular front k-member for my car. That would allow me to not only save wieght up front but also to take my pan off without removing the engine.