problem with top oven/grill on leisure gourmet classic electric?

good morning all, I have a problem neither top oven or grill will work on my leisure gourmet classic cooker, I think it's the micro switch thats operated when the top oven door is opened or closed. Can anyone please give me the routine for replacing said switch, I don't want to give myself extra work doing it if someone knows the easy way, thank's for any advice you can give.