0. switch off ignition, put the key in your pocket
1. lift fabric trim in the boot
2. undo two screws that hold the plastic cover in place, remove cover
3. disconnect the electric plug (AFAIR it is a snap on type with a protective hatch which needs to be released)
4. disconnect the two blue fuel lines by squeezing in the two white-ish squares on the fast-connects (some fuel may leak at this point)
5. now for the hardest part - undo the ribbed plastic flange - a special tool is recommended. If you don't have one, be imaginative - i used two flat head screwdrivers.