Dismounting the unit
1 Press the clip inside the front cover with a thin screwdriver, and gently pry the front cover free.
2 Repeat step 1 on the left side.
The front cover is removed.
3 Use a thin screwdriver to push in the clip on the left side of the unit, then pull out the left side of the unit until the catch clears the mounting. 
4 Repeat step 3 on the right side.
5 Slide the unit out of the mounting.
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