I assume you are completely removing all the pipework? I would.
Then, cut a short piece of the pipe, block one end with a bolt wrapped with plumbers tape and secured with a jubilee clip. Push the other end back onto the pump.
You could then either pull Fuse 40, or unplug the pump, or both. The plug can simply be wrapped to make it waterproof and tied back along the loom.
I did the same thing with wifey's car, but I simply swapped the washer bottle for a single pump one.
However, you may well have a fluid level sensor in yours and would therefore need to find a bottle that has the necessary float fitted.