Amber light has dropped out?

I have a Lamona HJA5110 range cooker. The Right hand side oven temperature (amber) light has dropped out. In my handbook it's described as "oven RHS thermostat light" and further on in the book it's called "the amber temperature indicator light." It's like a pilot light that glows on and off.
Theres a hole the size of a 5 pence on my console. What part should I order and how do I fix this please

Kate
September 2015