I'm not sure what you mean by "work properly", but it's a really easy swap. You'll need to trim the stems to the same length as the stock needle stems and make sure you don't push them down too far so they don't catch, but other than that, there's not much to it. Just mark where the stock needles are at idle, carefully pop them off (I used a fork and gently rocked it back and forth to pop them off), and put the new needles on pointing to where you marked them.