The buttons include two sided tape that is absolutely maddening to peel. The best way I found is to stick them onto the existing triggers first and use tweezers.
When applied to the back of the rubber buttons, the adhesive feels weak. I don't expect these to survive much, though time will tell.
The buttons also come with a little zipper case for some reason. I would have preferred to save a buck or two though I suppose I could use it to carry earbuds or something. Bit of a weird decision for a one-and-done kind of product.
Overall, I'm generally satisfied but I guess I expected something easier to install that would last longer.