I did mine a while ago, IIRC it was a 32mm but it wasn't a perfect fit but plenty good enough.
I big hammer helps to shock it off without having to try and lockup the pulleys, just keep beating it round and round. can't remember if it was LH or RH thread though.
A tip for refitting is to tighten up by hand then mark the stub and nut with tipex, so when you tighten it back up it's possible to see exactly how much. Mine went about 3/16" and has been fine ever since