Headset button nearly broken

The power/select button on the headset of my Index made an awful crack when I pressed it and now it travels longer than normal, I believe it is held in by tabs and only one side broke off. It is still usable for the time being but I don't know how much longer it will last with half the support. I didn't see a guide or part specifically for the button on the headset, so I'm wondering what do I need to replace the button if/when it breaks