Just follow the wire down from the button. You'll run into a connector that just pulls apart.
Let me ask you, is this the first 500 you've had. I remember when I bought my first one, ('91 CR) I had a real hard time starting it. So much so, that I thought I'd made a big mistake buying it. But it wasn't the bike at all. As a matter of fact, the bike started easy, I just didn't know how to start it.
If it is your first one, try this.
First put a new plug in it. Then, choke on, and make sure you don't give it any gas as you're kicking it. I like to hold my front brake with a couple of fingers. That way I know I can't accidently turn the throttle while I'm kicking. Get the kick lever up as high as you can, and give it a good strong kick. It should start in 4 to 6 kicks cold.
When it's warm, no choke, and give it about 1/3 throttle as you kick it. It should start on the first kick.
I hope this helps.