Dash buttons are designed to be disposable, despite being powered by a replaceable AAA battery. The case they come with is welded shut and can't cleanly be reassembled after opening.

This is a reusable case for a dash button. The lid can be removed with a fingernail or small screwdriver. After replacing the battery, the lid can be snapped back onto the body.

Writeup here:

https://blog.christophermullins.com/2018/09/02/reusable-dash-button-case/