How to change the pump and more on a bosch wff 2000GB/01?

Hi. How would I change the pump on a Bosch WFF2000GB/01. We are getting the 3 flashes code. The pump hums and then the control cycles to the end. If when the pump hums we whack the front of the fascia (with one of the kids old school pumps, not a hammer) where the pump is it kicks in, pumps and works to the end! I'm also fairly certain the bearing needs doing at the same time as it's really noisy on spin and the drum rotates freely but roughly by hand when empty. I'm a mechanic/MOT tester by trade so having a go at fixing it before condeming it is fine with me. I've read that the brushes last about 10 years, it's 12! Replace these aswell? The boss would like a new one though. Best option? Fixing costs against new equivalent. Thanks. Andy