Remove engine and put it on a stand. Rotate it upside down. Apply a ton of black RTV on the bottom the the block. Put oil pan on the engine, tighten up bolts. Let it dry overnight. Reinstall engine. Thats the only way I know how to do it.
If you can support the engine from the top, you can drop the K member instead of pulling the engine.
I would say not to use a ton, but use a GOOD bead amount of RTV on the pan .. we've done jobs where we tried to make it look nice and clean and use a bead and wasnt enough so it leaked afterwards.