I have the same problem. The JIS 000 tool works great on the joy con rails per step 5 but refuses to turn the bottom two 2.5 mm screws as in step 4. These bottom screws are noticeably smaller than the screws as in step 5. The JIS 000 does not get down into these screws. Hopefully they haven’t been stripped by the wrong tool. So is there a JIS tool that is smaller than 000? I’m stuck at this point…