How to put a new strap button on an acoustic body?

My wife bought me an inexpensive ($100) acoustic (classical) guitar for Christmas. I bought a strap for it, then realized that there is no strap button on the body! A really bad flaw since I can't use a strap.

I see strap buttons for sale, and I've looked at "how to" videos, but can't find one that tells me how to install one of those strap buttons at the body end of the guitar. Is it possible to do so, or is there an alternative product I could use? If so, and help and instruction would be greatly appreciated! Thanks!! -Don