The old shock pops off with a screwdriver, just pull the wire retainer off if there is one (usually is). Very, very easy to do.
Manufacturing a hold stick that involves drilling into the plastic seems like a bad idea (plastic may crack under pressure, for example) in addition to being more trouble than it is worth. You want to be able to adjust how open the door is, so that it is just right, basically fully open, it is nice to be able to fine tune the opening (by moving the stick) otherwise installing the new shock can be a hassle. A scrap 2 x 4 propped against the metal edge of the door does that safely and easily.
I have changed these things like five times now, this job is a 3 out of 10 on the difficulty scale, no need to over think it!






