RWB7 timeswitch and thermostat help

[Boiler_Numpty]

My mum recently passed away. The insurance company have said that I need to set the central heating in her house to come on whenever the temperature drops below 5 celcius.
I have no idea how to do this and have no manual for the RWB7 / thermostat. I've googled for a manual but the only thing I can find is completely useless to a central heating numpty like me. Can anyone provide (extremely) simple step by step instructions on what I need to do. Any help much appreciated.

 

[Echo the husky]

Push the select button several times on the the programmer until ON is indicated. Then set the room thermostat to an appropriate setting.