Originally Posted by ozzy1
It was not super easy (without removing it) but you do not need to remove the cross member. I used a ratching 14mm wrench, and a hammered out 14mm allen head. Hammering it out is quite easy. Flat head and a hammer. Ratcheting helps with what minimal movement we have because the member is not removed. If you get the wrench and the allen paired up and stick it through the limited space, you should be able to place the allen key on the fill bolt. Then since its ratcheting, things are little easier. Obviously, first attempt to loosen the bolt will be the tough part. Hope I am making sense.
I purchased an allen wrench off of ebay delivered for $6 and cut a piece off about an inch long if I remember correctly. Stuck it in the plug and turned it with an open ended wrench tiny bit by tiny bit. Worked great.