Before you begin the process of replacing a fuel injector or fuel injection rail, you need to think about safety. Always keep fire safety in mind when you are working with fuel. You also need to be sure you are wearing eye protection. Even if you've released the pressure in the fuel injection system, there could be some fuel flying when you start disconnecting high pressure lines and removing injectors.
Starting Out:
* Be sure to follow the procedure for relieving the fuel system pressure. Very important!
* Look over your car's injection system. Some systems are easily accessible and others are practically buried. Plan your attack so your job can be organized
* It's a good idea to get a fuel injector puller if you are removing fuel injectors. There are other ways to do it, but you risk damaging expensive fuel injection components.