I used some soapy water and the tires were cold enough and stiff that they laid near the rim and just a few presses on the tire it was able to touch the wheel and started filling. No fancy compressor used just one that had 120psi and 30GAL so plenty of volume.I did mine in a similar way with the front of the van in the air with the tire under the frame rail. Used a couple 2x4s to hold the bead back once I had it separated with the jack.
My next challenge was getting air into the tire fast enough to pop the bead back into place. With the valve core removed (they just twist out like a screw) and my air compressor regulator set up to about 100, it was enough.