Parts list:
1 16608aa020 Seal-fuel Injector x4
2 16698aa020 O Ring-injector x4
3 16697aa000 Ring-injector x4
4 16696aa000 Spacer-injector x4
5 16698aa010 O Ring-injector x4
Picture of parts list (credit to bsod2600)

Note: These directions are for removing the entire fuel rail, it could be done without removing the rail, but it's much easier if you do it this way. The old injectors WILL be stuck hard and if you can handle the rail, you'll have a much easier time. The only reason I could see NOT removing the rail is you want to save $25 only buying 4 new O-rings instead of 8.

By n2x4
1. Disconnect the 4 injector plugs, and unbolt your fuel rails. There are 2 bolts on each rail that bolt the rail to the manifold, and 4 8mm fuel line bolts that need to be removed.
2. Remove the injector "caps". These are 8mm as well. Then remove the old injector from the rail. This requires a bit of work as they're tough to get out. I used my 8mm socket and tapped them out with a hammer. After the old injector is out, inspect the inside of the fuel rail to make sure all the old o-rings came out.
3. Assemble your 440's with their hardware. Here's a picture of the greytop next to the pinktop:

By n2x4
Injectors and some of the proper O-rings. You need 4 of each of these:

By n2x4
I bought these injectors with hardware back in 2007 but never installed them. Per Kleinkid's instruction, I bought these other O-rings which aren't listed in the JDM FSM scan, 16696AA000 which goes up where the red ring was drawn:

By n2x4
4. Set the injector into the rail. It won't go completely in, so screw back on the injector cap to seat the injector the rest of the way. Here's what 440cc injectors look like in the rails. O-ring 16608AA020 is pointed out in red:

By n2x4
Reinstalling the injector caps and the fuel rail to manifold bolts calls for 17ft. lbs. DO NOT forget to reinstall the metal spacer/washer that goes between the intake manifold and the fuel rail. Forgetting to do so will bend your fuel rail

There are 2 other injector O-rings that I didn't list part numbers for as the injectors I purchased already had them installed. Here is a picture of all the o-rings that go on the injector, and their part number. Don't mind that it's got a yellow top, they still use the same parts. Thanks Kleinkid!

By n2x4
There are also 3 o-rings that go on the ends of the fuel rails between the fuel line.