It is covered in the manuals for the devices.
Eyewave screw is at the bottom, remove that and you should be able to slide the unit off to expose the bracket that is screwed to the wall.
The RWT721 is usually sides off the bracket, you can the look at opening the unit to take out the battery, unfortunately the way some people fit them makes access difficult sometimes.
Eyewave screw is at the bottom, remove that and you should be able to slide the unit off to expose the bracket that is screwed to the wall.
The RWT721 is usually sides off the bracket, you can the look at opening the unit to take out the battery, unfortunately the way some people fit them makes access difficult sometimes.