How do I get into my Zanussi 1083 ?

I think the belt may have broken/come off my washing machine. It fills with water ok, and will operate the drain cycle, but as soon as any washing is attempted (ie when the drum is meant to move) it trips my electricity supply. I think the drum is easier to rotate by hand than it was before, hence my theory about the belt having come off. However, to see whether I'm right, I need to get into the damn thing and can't figure out how to do so! Any hints much appreciated. Thanks.