AEG Santo noisy pump?

I've got a pair of AEG Santo upright Fridge freezers. One of them has become quite noisy when the pump is running - sounds like the familiar noise that all fridge freezers make, a sort of buzz that you know is definately a fridge freezer!

Anyway, Ive had a look around the back and it's the one on the bottom right as you look from behind - marked HQM 75AA.

Question is, can this be replaced by the user or is it a service call?

If I can replace it myself where can I get the parts from?

Is it definately the pump or could it be an issue with the electronics strapped to the side?

Any help would be appreciated!

Thanks