OK...so let me explain how I solved the problem, just in case anybody else decides to purchase these headers from the Bronco Graveyard. These solutions were not my own, but belong to another bronco owner with more knowledge than I.
On the drivers side, we disconnected the front driveshaft, then lifted the engine off the mounts. We did this by disconnecting the mounts and used a car jack and a block of wood under the oil pan.
On the passenger side it was a little more complicated. We ended up removing the transmission oil filler tube (I guess my transmission needed to be serviced anyway), then we stuck the same jack and block of wood under the rocker panel (towards the front under the door hinges) and jacked the body up just enough to compress the bushings and lift the body about 1/4 inch. The header then "slipped" into place. Hee Haw.