Newby here, have a little bit of an issue. Cleaning my new M9, disassemble the extractor following the tutorial. When trying to put it back, it won't go in properly. The head where the spring attach to is rounded as compare to the flat/bevel from the tutorial. So every time, it is closed pressed by a small flathead screwdriver, it is always slipping from the retainer. The surface is covered by something that is rather slippery which probably on purpose. Attach is the picture of the spring attached to the rounded head. If it is not clear, I can try to put up another one. Any advice on how to put it back? Thanks for your advice.