Just to wrap this up....all done a running like a champ. Thing is, why the hell didn't ford just make the hole larger? In the i levered the hole outwards so the lip of the hole was vertical. It was still a tight squeeze to get the lock ring out and but better than fannying around with dropping the tank. So for those that may stumble across this thread it is doable. You'll have an ugly looking hole but who cares when the seats cover it!