This should be a simple, simple item to install. It's not.
The gas cylinder arrives at your doorstep in its fully extended, "Ready for Action Now, Sir!" state. This is problematic for a couple of reasons:

a.) The distance between the attachment points on the bumper is almost exactly 3/8" of an inch shorter than the distance between the attachment receptacles of the fully extended strut, and

b) The internal gas pressure of the fully extended strut far exceeds the ability of the frustrated installer to compress the cylinder that lousy, stinking 3/8" inch. FAR exceeds it.

In fact, during our investigation as to why this item is not a registered weapon, illegal in several states and counties, we determined (using a 10-ton bearing press) that the pressure required to compress the strut to a useful length is approximately 100psi. Anecdotally speaking it was also noted that unless the strut was placed exactly perpendicular to the plane of compression, the amount of pressure required to launch the strut out of the 10-ton press like an unguided Polaris Missile was just shy of 99psi. You can see the problem.
After much bitterness and regret that we ever started this particular procedure, up to and including several variations of ratchet straps, vise grips, furniture clamps and a really big hammer, we were forced to resort to reverse-engineering the assembly procedure for the entire swing-away system. In other words, we had to take the whole damn thing apart. Ultimately this approach yielded success, although we had to call upon our patient spouse in order to meet the minimum number of hands required to hold the business end of the swing-away carrier up as we madly searched the garage floor for whatever missing part just went "ting!" as it bounced its way underneath the now no longer roadworthy Vanagon. 1.5 hours of frenzied labor and a vast amount of cursing is why I give this product a -2 Star rating and a 3 wrench Skills Required.
You asked.