if you are able to reach the bolt with a wrench, i would suggest a ratcheting wrench, if not and it is in a strange angle, get a cheaper wrench and bend it with a vice to the desired angle. though i would look for as many alternate positions to take the bolt off as possible(like under the van or on its side), but anyway a have almost a whole set of bents wrenches for just that purpose, and they work great.