Injectors Rebuild?

[ATX5]

Heard some unusual taping under the bonnet last night and found that one of my injectors in making a little too much noise. I did the old "ear against the screw driver end" trick and found that it was making an awful racket inside. So bad that i could feel it vibrate through the screw driver. Has anyone removed their injectors themselves. If so, how hard is it? I was quoted $220 - $250 r, r & r (remove, repair & replace) all four injectors. I think I could cut the price down a bit by removing them myself. Any info would be helpful.