how do I check and change the brushes on my servis 1100?

My washing machine has power but is not really working...I think it may be the brushes. There's grey stinky stuff in the filter compartment. How do I check them and where exactly are they? I know they are near the alternator but this one looks different to the one's I have done on my old machine. Are they screwed inside the brown casing? My friend is suggesting I check the circuit board instead of the brushes. Can someone give me advice please?