How to replace the door seal gasket on a Miele W504 washing machine?

Can anyone provide instructions on how to gain access to replacing the door seal gasket on my Miele W504 Premier 500 washing machine?

I have the part, and tools to carry out the job, just no idea on which way to tackle the job - the correct way without calling out a Miele service team.

Can I do it myself as I am DIY minded and do not want to let this task beat me!

Any help would be grateful, as I am a bit short of cash like everyone else out there at the moment and hope I can avoid incurring more costs right now.