Loosen the fuel rail and move it out of the way. You don't have to completely remove it but you can and if you do you may as well go ahead and get new o-rings for the injectors. Whatever you do just be sure the injectors are firmly in place when you bolt it back on! Also since you're under the hood anyway you may want to consider going ahead and changing all the plugs and coils. You can get a set of 8 COP's on ebay for around $100. Alot of us have used them and have had no problems. You'll want to use Motorcraft double platinum plugs. Oh, and use anti-seize on the plug threads....it'll make your next plug change a snap!