Pulling the valve covers does not require jacking the engine up, just some patients and a bit of wiggling.
A 12mm - 1/4 drive - wobbly will make this task much easier.
To replace the standpipes the covers do have to come off, but the HPO rail can stay. There is a 10 or 12mm allen that holds them down, once you remove the fitting the pipe might come along with it - or you might have to dig it out with some needle nose pliers. Dummy plug is the same, just in the front of the rail - and no pipe attached.
If you have never worked on a 6 ohh before, and are fairly mechanically inclined....I would rate the work you are looking at doing a 6-7 on the skill/ patience level. If you have spent some time under the hood of a leaker, its just another job.
