Unpair Wireless Smart Dimmer

Hello there,
I paired my wireless dimmer switch with 2 ceiling lights. But I want it to work with only one. I cannot find a way to unpair it or reset it. Resetting the ceiling lights doesn’t work. Removing the battery of the switch doesn’t work. I can’t find anything in the yeelight app. My ceiling lights are YLXD50YL
Can you help me on that?

Thank you!