Many sewing machines need to have the feet or throat plates unscrewed to be removed or put on. They usually come with a screwdriver that is too large for the area of the machine it should fit. WHY? I don’t know, but you don’t need to put up with it—there is a solution! Try an offset screwdriver. I find the 7mm one fits most machines perfectly. If you can’t get the 7mm one, try wrapping a little masking tape around the 6mm one. They’re probably available at the hardware store, a specialist hardware store or may be have to be a special order. Another option is to get a small set of screwdriver heads that fit in electric drills (instead of standard drill bits). They aren’t as user friendly as the full screwdriver but they should do the job.