I have purchaced a new repeater indicator for my 2011 Ducato Motohome due to an argument with a passing tree and now wonder how to fit it?

I understand that I need to remove the large actual mirror to reveal 2 screws holding the indicator light in position.

Please can someone tell me how to do this without breaking the mirror?

You don't need to remove the glass just push it in on the side near the indicator.You will see the screws holding on the indicator then.

Thank you for your help. It all worked exactly as you said and now all is restored to normal!