matt, look up the thread on catch tank from about 2 weeks ago. I explained quite thouroughly what you need to do. very easy mate.
lemon, yes you can get the injectors out through the top with a suitable sized spanner. Be careful with the o rings though (the rings that sit between injectors and manni like a seal) else you'll need to get new ones.
btw, i;ve taken mine off several times and never took out the injectors. Think injectors can only be properly cleaned with some technique of which the word sounds very expensive/fancy lol haha...