Mike - the spur is a scale, and it can come right off (like it did in the picture). I've had a few of them do that - a little super glue will fix it.

To get the scales off, I use a dremel. Iteats them right off. I use one of the little stone bits.

Tip: Fingernail polish works wonders - Coat your spurs with clear fingernail polish, and it fills in all the imperfections, and gives them a nice, glassy look.

I also coat the bony part with white fingernail polish, which makes the bone nice and shiny white. Looks really good.