[M100]

I cut the gear shaft that switches between high and low gear and just pulled them right out the side. I dont think there is any other way. I think the gear selector is put on the one shaft and then the rod is put through the middle of the selector to hold it in place. The rod seemed to have been glued or pressed into place, when it got hot and I'd cut through it it actually started to drop out the bottom. If you look close on your own you can see it.

A crude approach not many would intentionally take - although it would be interesting to see the remains of the bits you removed!

For fitting a belt drive surely you really only need to remove the top gear with a cross point screwdriver? My own reasons for dismantling that area is to remove any casting sand/grit that didn't get cleaned out of the casting so hacking bits in half to remove them isn't on the cards, but I'd anticipate using the mill for some time with the existing drive arrangement.

Medium term I'm probably going to a multi-groove belt drive with the existing motor or with a VFD driven motor. Long term I'll be replacing the entire spindle bearing assembly to accommodate significantly higher spindle speeds