Farenheight to celius conversion

[gazm]

Hi everyone

My RR has come back for a service and now reads the outside temp in oF, for the life of me I can't get it back to oC.

Can anyone help

Cheers
Gareth

[gazm]

Its a RR3 (02) HSE with the sat nav screen. I'm sure its there but for the life of me I can't see it!