This is just a derivative of a great spool holder from Charlespax, adapted with a plate to fit the BFB's printers. you don't need to drill to damage your printer to fix this stuff, this is a hook up thing!

Download my STL files, print them as is. There is a big and a small holder for different spool size. (750gr/2.300gr) I used ABS with 0.5 layer thickness, infill of 40%, no raft, no support. Use 2 flat head screw of 8mm to assemble the plate to the holder. No need for bolt, normally...