How do I clean the fan in my fan assisted oven?

[totaleclipse]

Food is cooking faster on one side so I assume the fan is dirty and not working properly, any ideas how to clean it?

It may be the fan is unbalanced - is it noisy? The actual fan should have a cover that can go in the dishwasher.

it is noisy accasionally, it makes a sort of vibrating noise, will check it out, thanks