Use either a guitar pick or thin sheet of metal, pry open the grip sensing panel.

There are five plastic clips around and under the grip sensor. Use the tool to pry up around the sensor to lift it out of the handle.

Tuck in starting closer to the top of the controller, and apply force to lift the panel away. Move further around the sensor, using a second tool if needed to keep the grip sensor off of the handle.

With gentle force, the propped grip can be removed from the main handle.