1. Power down your system (switch off at the mains) -
2. Unscrew the cover and remove the from the unit. 
3. Disconnect one of the terminals connectors from the battery back-up.  
4.  Reconnect the terminal and screw the cover back on.  
5.  Power up at the mains and bingo!  
Job done!
If you are unsure always consult a qualified electrician/alarm fitter.
                
 DIY man
                
 September 2009