Pull Dog

Talked to a fellow in a campground this past weekend who had an 05 Cummins like mine. He told me a horror story about being on the road somewhere and the truck quit running. Had it hauled to a garage and it cost him $3000 to get a new injector pump installed. This put me to thinking about it so an Internet search turned up several OEM Bosch pumps at around $800.

So my question is this, how hard is it to replace an injection pump. What are the proceedures to purge air from the system after it's replaced. Is this deadly pressure still in the lines when the engine is shut off?? I like to be prepared with some knowledge just in case I'm ever in a situation like this poor fellow was.