Fairly easy job to do, after I did it. Draining the oil rail is simple. You rap the rear allen head, that is located under the valve cover, with a punch, to keep yourself from stripping it if it is too tight. You're not trying to turn it, just breaking it loose. Crack one of the outside lines on the rail, and the oil will flow to the rear, and down into the pan. After you have removed the lower bolt on an injector, take a rubber mallet, and rap the top of the injector fairly hard, to break it loose. After the injectors are out, wipe the liquid out, and take a toothbrush to the gunk inside the injector cup, and wipe it clean with a rag. I removed the glowplugs, so that after the injectors were installed, I replaced the valve cover loosely, and then spun the engine over a few times, to purge the cylinders of any liquid that was inside of them.