The washer pump fits in a rubber filter on the resovoir. You'll have to get behind the inner wheel arch by the resovoir, pull the motor out, pull the rubber filter out, clean it (probably got snot type stuff on it), flush the bottle out with hot water, refit and flush hot water through the system.
I suggest using a screenwash (not fairy liquid) and fill up with hot water to help stop anymore snot blocking things up.
Some people cut the bottom off the filter. This might stop gunge blocking the system as the pump may break it up but bits of grit will still pass through and block the jets.
His Nibs
March 2009