97' Jeep Grand Cherokee, 4.0L valve job

How Hard is it preform a valve job on a 4.0L inline 6cyl., With a automatic transmission, 2X. I was advised by a mobile mechanic that this was a very tough valve job because of the fuel injectors. They were to be very fragile, and if mishandled could be fatal to the injector. My view is that I do not even have to touch the injectors, or relieve the fuel presure system. I :shock: f I leave them in the combination Manifold (intake and exhaust), and dissconect the manifold from the head and wire it up out of the way(even only a fraction of an inch), so that I could remove the head straight up and out. This to me seems logical, could you please shed some light on this subject, I would greatly appreciate it.