Igorenched, "what is the preferred method of undoing the lower inner nut? Yeah, that hard to reach sumbich, the 15mm one. The three 17mm ones are easy to get to but this last bottom one is driving me crazy." Igor, IIRC and it's been a while... I believe an S shaped box wrench does it. (...and it may have required some further bending.) Bill~wrench~M