Oven fan not starting

[magicdaps10]

When i press the button to start the fan it does not work.When i hold it down and keep my finger on it,it works but as sson as i release it stops.

The light switch works so i think the switch has gone.

How do i replace the switch?
Bare in mind i am a complete novice!

many thanks in advance.

 

[sparks1234]

Bets thing to do is look in your local rag paper and you should find in the back people that specialise in this kind of thing and normally they are cheap enough, ovens and washing machines aint worth getting into