Captain Spoonhandle's instructions work, but it takes a fair time to siphon the fuel out and clean the tank. I used a 26L handled flexible bucket from Asda to collect the fuel. You can then hold the handles together and pour the drained fuel into a 25L empty cooking oil carboy from the local chippy.
A few extra points.
After removing the grommet like cover before taking anything apart take a photo or two with your mobile or digital camera. You'll need to replace the O-ring seal, its part no 153141 so get it from your Peugeot dealer before you start . Its black and costs about three quid, the blue seal doesn't like lengthy exposure to biodiesel. Remove fuel outlet and return pipes by pressing the white clips on the hose fittings. Then remove the electrical plug. Peugeot use a special tool to remove the locking ring but a rubber mallet tapping a well fitting screwdriver blade in the one of the lugs at the top of the ring works.
Clean the locking ring after removal and note the small triangular arrow moulded in the top. Remove the pump/sender unit taking care not damage the float or the float arm. Empty the tank as described by the worthy Captain and re-assemble. When replacing the pump/sender mind the float arm and align the arrow on the body of the unit with the arrow on the tank. Don't forget the O-ring that goes between the pump/ sender unit flange and the tank. The pump/sender body is made of acetal which is harder than the polypropylene used for the tank so don't force anything. The tank arrow can be hard to see as its just below the metal opening where the grommet like protector sits. (With the fuel nozzles facing the engine the tank arrow's about 90 degrees to the nearside and almost on the tanks top face.) Refit the ring and tighten it so that that arrow on the top of the ring aligns with the arrows on the tank and the pump/sender unit. All arrows should be in a straight line.
Reconnect the pipes, then the electrical connector. Check your work against the original photo and adjust if necessary. Finally refit the grommet like protector with arrow on it facing the front of the vehicle, refuel and you're done.
Finally my thanks to Captain Spoonhandle without whose guidance I would have never have done the job.
Won Fu El, March 2010
