It is the biggest pain in the *** you will ever encounter...You can only drop the pan about 3/4 of an inch, then it will get caught betwenn the pickup tube, and the crossmember...You will have to undo the two bolts to the pickup tube (major pain in the ***) in order to get the pan off. BTW getting it back on is even harder. My suggestion is to support the engine form the top with a crossbrace, and completely drop the crossmember from the car. When we did it we undid the motor mounts, jacked up the engine and dropped the crossmember about 2 inches, and still had clearance problems...this was even with the tranny out of the car. The pan needs to be able to drop strait down about 6 inches for clearance. You can not just drop it and slide it forward due to the oil pickup. It looks like you can, but you can't. For what it's worth, make sure you have access to a lift and completly drop the crossmember...your knuckles will thank you for it, and it will be a lot quicker too.
Matt
BTW if you go through the trouble of dropping the crossmember, you might as well just leave the engine attached to it and drop the engine with it. I can take the complete engine and transmission and crossmember out of an LS1 in about 45 minutes with air tools and a lift. Just undo your strut tower bolts, wiring harness and a/c lines, and drop the corssmember. Then but the engine on a stand and drop the pan. Doing the pan with the engine still in the car took us about 3 hours. Next time I will just complete drop the engine.