Make sure the reservoir is as empty as possible - it holds a lot of water and will be very heavy if it's full.
There are just a few screws holding the reservoir in place (I think only two - I forget, but they're easy to see).
As you manouevre the reservoir out of it's location you'll find the washer pipe is held in place with four plastic tags. These appear to be plastic-welded in place but they're not, so don't snip through them with pliers, like I did
Just put a screwdriver under one end, and they will pop out (you have to do this one-handed as the other hand will be balancing the reservoir - that's why it's best empty.)
There are also two tiewraps that hold the pipe to the inner wheel arch. Again, don't cut through them. They're special wraps that end in a plastic nut, which fits onto a stud on the bodywork. It's only after I'd cut through them ( again!) that I realised you can release them with a small screwdriver. (And there's no easy way of fitting an ordinary tiewrap here).
Once the pipe is free you can undo the electrical connector to the pump. Then pull the pump from the grommet in the reservoir. The pump can stay connected to the car, to save detaching the pipe from it.
Refitting, as they say, is a reversal of the removal operations!