Push the entire unit up from the bottom,then lift it of it's mounting screws.
The battery compartment cover can then be removed and new batteries fitted,3x 1.5 AA going on the paper work I've managed to obtain.
Remember the code will revert to 0000 so you need to change it if required.If the fault is with the batteries then I can give you instructions on how to change the code for your own.
No point posting it at this stage if the things knackered.
e manno, July 2013
