Actually, yes, I'm a little familiar with your situation -- I have a friend who has a shunt, has had it for a number of years and so far has never had to have a revision, surprisingly. As her doctor says, if you are functioning fine and are not experiencing typical symptoms of a failed shunt, there is no need to get in there. She considers herself very fortunate, needless to say.
I suspect many of us have to read technical instructions carefully more than a couple of times and even at that are still uncertain about how it's all going to go until we're actually in the process of doing whatever the task is. I know *I* do, anyway! Just taking a deep breath and plunging into it, doing the hands-on thing, usually works out for me. I do like to have the instructions right there, preferably written out step-by-step. It's interesting how often, though, something is left out or the process isn't quite the same as described in some way, and that's when one has to just trust that doing "x" "y" or "z" will get the job done anyway!
. The fewer surgical interventions one has to have, the better, as far as I am concerned!!