Fender709

yea, i just want to take off the buttons and change those, ive already take the machine itself off of the hieadstock, and i unscrewed the screw that conncected the button the the rest of the machine, but it still won't come off

I have an ovation acoustic electric guitar, and i want to change the buttons on the tuning machine heads, but i cant seem to figure out how to remove them, any ideas guys?