Fuel Tank Filler Neck Grommet

If an A body tank will come out without removing the filler tube, it seems like it would be easier and faster to drain the tank and remove it, replace the grommet, grease the tube and slide the tank back up into place. I've done B & E body tanks like that, but honestly can't remember doing an A body that way....or if it will even come out not removing the tube....because it wraps around the spare tire hole.