a bit late, buuuuuut......i've yet to do this on an xj, but it's worked for me several times in the past. a tad redneck, but it works(a crusty old mechanic showed me when i was 19). get a nice strong breaker bar, and a good impact socket. put it on the hb bolt so that the breaker bar is wedged against the framerail(if one has the room-works on many old fords and my 22re 'yota) or the ground. with the coil wire DISCONNECTED, quickly BUMP(not a full "crank") the starter with the ignition key. the crank trying to turn clockwise will knock the hb bolt loose. if you are stupid, please don't do this. not my fault if you didn't look to see if the fan would hit the breaker, etc. just something that has saved my airtool-less butt many times.