Does anybody know how to put this (https://www.us.kohler.com/us//productDetail/screw/626005.htm?skuId=589148) set screw into a Stillness Kohler shower handle (https://www.us.kohler.com/us/stillness-rite-temp-valve-trim-with-lever-handle/productDetail/handle-trim/1270658.htm?skuId=1270570&brandId=empty&)? I can't figure out the right hex key to make it work. It seems like a 2.5mm is too big, and a 2mm is too small. Do they make 2.25mm hex keys? Or is it perhaps a proprietary Kohler tool that I'm missing?