How do you remove and test diesel fuel injectors?

How do you remove and test diesel fuel injectors?
Removing the injector is fairly simple. There is a fuel supply line (steel line) to each injector. There is also a return line (smaller one). Both of these lines will have to be removed. On the return line be careful not to lose the little compression washers. Remove the two bolts that hold the injector in place. The injector should pull out. Be careful not to lose the copper washer that usually comes out with it.Inspect the end of it. There should be tiny holes in the end where the fuel sprays out.Unless you have a injector tester you will have to take them to a Diesel mechanic and have them tested. They will hook them up to a machine that can apply the PSI required to see if they are working properly. It shouldn't cost that much.