Injector bush removal

http://www.ferrarichat.com/forum/308-328/220728-85-qv-injector-seal-question.html

Morning chaps
The thread above lists the 2 different types of injector bushes and how they are used on our engines (well not all ours).
I have the later model engine so mine has the push in bushes rather than threaded bushes.

Has anyone had theirs out and can they help with a lil info...like did they have to use a specialised tool or the like or how did they get under the bush to pop it out.
Pulling the nozzle out of the centre is not the option as the seal is as tight as on the nozzle and then you are still left with the bush in place.

Don't want to screw this up

Regs
Peter