The drain should screw out but it's not easy because you'll have to hold the Ptrap while you twist it off and I bet you have almost on room for your hands underneath the drain pan. If you can get a pipe wrench under there and hold it then your friend can work from above and twist it off.
If you do change it out then buy a drain plug to keep it covered, I cover mine with a drain plug. I'd take a pic but it's 3:00 AM and Tunce would have a fit if a went outside to take a pic. now!
2010 Jayco Hybrid EXP21M
2013 Toureg TDI