Nissan Repair: 91 Maxima # 4 fuel injector open, clam shell, vacuum leak

Question
-Von, If I only have 1 injector bad do I need more than 1 O-ring and just ask for an intake gasket, no other gaskets? There are abunch of allen screws holding down intake but it looks like a clam shell. I'll have to get at the 2 small bolts that hold the injector and the lower portion of the intake covers those bolts. By just removing the allens will the whole intake come off? Any special ways to remove or install injector,(lubricant etc, never done these before always carbs)Thanks Joe------------------------
Followup To
Question -
Von, I don't have a manual for this car but looking at the top of the motor and where the injector is I seem to have a situation where I'll have to remove a whole lot of stuff in order to get it out. It's a 3liter v6 and what exactly should I take off and not need to take off? What gaskets and hoses and parts will I need besides the injector? I could probably find some of the injectors at the bone yard and just check them for resistance. Working unit reads about 12.5 ohms at least on this car. Any help would be appreciated. Thanks, Joe
Answer -
Joe,

You will probably need a set of orings for the injectors and an upper intake gasket.  Yes, I love the wrecking yard as the injectors are cheap and if they are clean and the ohms check right you are ahead of the game.

Answer
Joe,

The only thing you need to install the injector is 30 weight motor oil to lubricate the new o-rings.  You buy a set so you do not get a vacuum leak and you only replace those disturbed by removal.  I only replace those that are bad but since you car has some miles on it I would do them all.  The upper intake might not have to be removed if you can get access to the side that has the leaky injector.