Any pointers on how to go about doing this? I've seen references to
fitting the new seal to the drum first and then the door?

There's a Haynes manual for washing machines, in case you ever get stuck.
Useful to have around if you intend to service your own.

http://www.amazon.co.uk/exec/obidos/...379496-6957236
http://makeashorterlink.com/?Q13022377

Christian.