Not removable. They are on a painted rack which is presumably steel tube (anyone got a magnet?). They appear to have three bolts two at the back and one underneath (I've got some difficulty bending over). The rack supports the box underneath... and I'd say would be a bit of a weapon with the box off.
I'm not a fan of hard boxes. If you get a leg caught.... bang - the box busts the ankle. I'll take soft bags EVERY time in offroad conditions... and still prefer them onroad.
Sure... I understand the protection of equipment issue.
One very nice thing about these boxes... they appear to NOT add width to the bike. I like my handlebars to be like cat's whiskers.... if the bars fit through, everything fits through - and that's never more important than when riding in Asia. I checked the width with my walking stick, then compared it to Phillip's CRF. Exactly the same width.
If I had a CRF and if I wanted hard bags, I reckon I'd chamfer the bottom leading edge of the box. I also reckon I'd find some Dzus fasteners and change the way the bags attach to the racks. Add a soft strap handle to the top... some tie points for soft luggage - and they'd be top class