You really don't have to drain it. Fluid will run out of the lines when you disconnect them. I use caps on them. Leave the yoke in the tranny so fluid doesnt run out. I usually stretch a bunjy cord around it so it doesnt fall out while taking the tranny out. If you want to drain it, remove all the bolts on the pan except a few on one side. Slowly loosen the remaining bolts without removing them all the way. The pan will start to slowly drop at an angle and the fluid will pour out on the low side. Once u get most of the fluid out, remove the pan. U have help getting that 400 out?

If not, try a piece of wood on the jack & a ratchet strap around the tranny. As you can tell, I work by myself a lot....
Scott