It's not hard, you just have to be careful not to tear the o-rings upon reinstallation. Vaseline rubbed on the o-rings will act as lube to help them slide in. (<-----quote of the year) Seriously though. Here's a quick run through:
1. Disconnect negative terminal on battery ( normally I don't do this. It is always the first step of everything and I think it's stupid, but in this case you are dealing with gasoline, SO MAKE SURE YOU DO IT! You don't want any accidental sparking and catch your car on fire)
2. Open the gas cap to relieve pressure
3. In between the Valve cover and the intake manifold is a black plastic thing with some grooves in it. That is the wire cover for your fuel injector harness. And the fuel injectors and their wiring are undeneath it. Disconnect the little black rubber hose that goes to the EGR that sits on top of that thing. Then that plastic cover has 2 tabs you have to pinch while lifting it. It will come off.
4. With a rag underneath it, Slowly open the banjo bolt holding the fuel line to the fuel rail. Fuel will come out. Be ready to soak it up. ( it's not much) There are 2 washers there also. Or maybe just one, I can't remember. Honda recommends replacing them. They are a crush washer. You can reuse it if you want, but if it leaks gas and catches your engine on fire, don't blame me. Also they are easy to lose, so if you are gonna try to reuse them, be careful.
5. Unplug the injectors from the injector harness.
6. There are 3 (I think) nuts that hold the fuel rail to the intake manifold. Take them off.
7. Very gently (especially if you aren't replacing all of the injectors) try to wiggle the fuel rail and pull at the same time. It will eventually come off and probably spill a little more fuel.
8. Pull the injectors out.
Like I said the o-rings are easy to tear when taking this apart and putting it back together. And I think one of them isn't available separately at Honda, so.....be careful. If you take your time, you should be okay. I did it with no instruction. It's a pretty straightforeward procedure. I may have left some stuff out, but that's basically it. Once you get it all back together be sure to check for leaks with the engine running. You don't want an undrhood fire.
Also while pulling out the old injectors, be careful, watch for the rubber and plastic o rings that are in the manifold. They can drop through the runners and be lost. Then you have to buy all the o rings for the injector as a package and its like $10 IIRC. Good luck.