Holy **** man, you do not have very good luck with your car. You will have to remove the K member or take the motor out. Im not sure if you can slide it out with the K member in place but I wouldnt think that is a good idea.
i just replaced mine. Get the FRPP pan if possible. It's $33 vs. around $100 for the OEM pan. I beleive you just have to jack the motor up a few inches if you planning on just changing the pan. When i dented mine i went ahead and pulled the engine and swapped heads and installed long tube headers. It was actually a lot more work than i wanted to do. I suggest just changing the pan and you'll be rolling again in no time.
no you can't just go under and slide it out. it has a slight front sum that prevents this from happening. Therefore you either have to drop the k-member down or raise the engine about 4 inches.