When you look at the nozzle, you will see a white part sticking out of the bottom, pull that out and you ahve the thing in 2 pieces. It snaps back no problem. Now, the white part has a gray piece sticking out, thats the bottom of the needle sitting inside a spring. pull that out and the spring should still be wrapped around it. You don't really need to take the spring out.
After you are done airbrushing, just dump whole nozzle in a container of windex. After a few hours or overnight, take it apart to wipe apart any paint. It should just kinda drain onto a paper towel. Put it back together. Takes longer to write than to do.