shove a piece of threaded rod, thru the section, add nut/washer/nut on each end, tightening well, then use that to unthread the pipe from the case.. probably $5 in hardware at Lowe's.. to make the removal tool. Depending on install vs removal, you may have to swap ends with wrench, on which direction you are turning it with the wrench, i.e. inside, or exterior.. but I think you can get the drift of it from that. good luck, you can do it.
For removal, you will wrench from the inside, that will unscrew the pipe, for install, you wrench from the outside, and that will tighten it back in...