Help replacing a jeans button Sewing Machines Parts and Sales in Los Angeles

Hello!

I lost a button on a pair of jeans. Luckily they came with a replacement button. But how do I “install” it?

I googled and found tutorials, but my button is different. It got a hole in it so I can’t just hammer it to deform the nail to keep it in place. And the nail is smaller then the hole, so it doesn’t just snap together.

This is what the button looks like:
http://m.imgur.com/a/9enZd

Do I need some special tool?