As described. The horn needed to be trimmed and resized a bit to fit, then the snap in added, and a curve added to the bottom to match the curve of the headband. Without it the horn stands too proud of the band to look decent.
I left the stud a little long, and would recommend using a soldering iron to melt the excess into place. The horn is very long and just the snap wasn't enough to reliably keep it in place. Hot glue would probably also work well.
The author remixed this model.