I just installed 3 of them.
The finish rings at each end should pop off since it is a tight fit and they are usually installed by pressing on them of hitting with the heel of the hand. Carefully work a thin blade under a place on tap it in and possibly give it a slight twist to pop it free. Just slide the rings away to the center section to work on.
After they are off you will see a stainless flange that is welded (nice machine welds) to the ends of the exposed rails.
There are usually 3 holes in the flange. Usually they are used long wood screws into the studs or 3/16" toggle bolts depending an whether the holes hit studs or not. If that is the case, just unscrew the 3" long screws. I installed mine through the shell of a fiberglass shower insert.
If installed properly, they will take a very heavy load.
They are made in China, but a under the name of many different suppliers and are a very good product. I put in 2 and was so pleased, I finally found spot for a third and it is just used as a wash cloth rack and a ledge for shampoo bottles since is works better than the molded shelves.
If they were installed according to directions, but is is always possible for someone to try an adhesive, but that would not hold any near the capacity of the handrail.