I didn't replace them. I just removed them. I also had to remove one from the foot controller. It was backened on the end. This machine was loaded with them. I wasn't planning on all that, but I did know that my machine was a fixer upper when I bought it. I've found a couple more issues but am working my way through them. I was able to try a few stitches last night. I'll keep working on it. I think I am going to love this machine. I've given it the name "War Horse".