those bitches are loged in there when i did my swap i tore mine down and had it rebuilt and i'll tell you what my injectors were the most pain in the ass thing to get out and i had the rail off. i still had to soak them im wd 40 and spin them around in the rail to make sure the wd40 got in then press them out through the back side. id say try spining them while spraying them. but honestly if you plan to upgrade your injectors in the future id bite the bullet and do it now and pull the plenum and the rails. at least you could give it all a nice cleaning