To mount my feet, I put the whole thing together first, and then predrilled those holes. To predrill them in the right place, I actually printed an extra foot, but only the first 5mm or so of it. That gave me the “footprint” that I could put in the right place and drill through to get the holes in the right place. Then, yeah, you need to have a long screwdriver or bit extension to put the screws in.
Reply To: Cant Reach bottom feet holes for screws