How to reset the bell tamper on 9651 scantronic system?

We have had to remove the bell box we have now placed it back on the outer wall and I need to know how to reset it
It is saying call engineer
Peter offord, July 2015

piss off you useless idiot

peter offord, August 2015
Car alarm, I don't think so

Get it right, August 2015
link Click here to see other fixes for Scantronic.