Simply glue a bead of your choice that is the correct size on the top of the antenna. Be careful not to get any glue inside the device. Super glue will work.
Wow, cherryxz, that's an awesome collection!!! I like the way you displayed it--rainbow style. And yours is too, EMF. I just added an aqua Hitorikko to mine. I never had one, so it will be something new and fresh.