The key steps are drain, pump removal, filter cleaning, pump re-installation and refill.

Most DIY kits include the necessary bolts and o-rings. I'm not sure if VW actually clean the filter... I suspect they simply drain and refill.

It is well worth doing the filter - there's lots of photographic evidence of the filter being crudded-up out there in the big wide internet.

EDIT: Do'h... two minutes too slow!