The Rosso twins are
Join Date: Oct 2011
Location: United Kingdom
County: Tyne and Wear
I took mine out on my 147, pretty much the same as the GT, PITA of a job, but I did mine when I did the inlet manifold so I could refurb it so I got it out the top of the engine bay.
Looking at the space available I would say normally it would have to come out the bottom way, might involve removing the O/S drive shaft, but if not it will be a tight squeeze.
Sure someone will come along who has done it without half the engine already out.