I put side sound ports in all of my ukuleles. They send sound to the player.
First, a veneer patch is glued inside the instrument. The grain of the patch opposes the grain of the side, thus protecting the side fr0m a split at the sound port hole.
The hole is begun by simply drilling lots of little holes with the Dremel , then with a sanding drum in the Dremel, the oval hole is carefully shaped to accept the wooden oval ring.
When fitted in it is fixed permanently with super glue. And that is all there is to it.