If I were you, I would approach one of the Canon repair centres. Even if you do identify the problem and the parts needed you risk introducing a lot of dust when you attempt a repair.
If it is under warranty I would maybe plead ignorant and see what they say. A bit naughty I know.
Even if you do get charged for the repair then it is unlikely to be a big cost. Certainly less than the extra damage you could cause by attempting to fix it yourself.