Any experience on unregistering your bicycle on kouban?

I'm in Tokyo, but perhaps the rule is the same across Japan (?)

Anyway, I'm wondering if I can cancel the registeration of my bicycle at any police station or does it have to be in a bicycle shop I bought it from?

Also, I think I lost the slip of my payment years ago. Can I still unregister it?

Thanks in advance! (⁠ ⁠╹⁠▽⁠╹⁠ ⁠)