They also are hard to remove without damage if I recall correctly from when I tried to remove one. Are they not available new?
On the flip side, you can unclog them by taking a thin strand or two from a piece of stranded wire (14 gauge for example). Use the wire to "ream out" the nozzle while spraying once in a while. If you have the hose off the nozzle you could try to clear it by blowing air in the reverse direction.
All this will probably reveal to you that the nozzle is adjustable. They are small balls with the outlet drilled into them. With the wire inserted into the nozzle you can change the position of the ball, relative to the point on the windshield where you want the stream to hit. There should be two streams from each nozzle.