How do I change the heating element in my Bosch Exxcel model wfl2463gb/12?

Everytime my washing machine goes to a hot wash the RCD trips out in the garage. We beleive this is down to the heating element as when the machine operates on a cold wash only it runs it's cycle without problem. Can you tell me if possible how to change the element and if you think that this is the cuase of the problem too.