There's a metal piece that sits inside the handle, and clips onto a tab in the floor pan. Often, the button will rotate off of a siveling pin inside the handle, and the lever will no longer lock. Chances are good that your handle is still ok, but you will have to disconnect the e-brake cables and remove the handle to reset the swivel pin onto the push rod. It'll take some figureing out to make it all work right. I usually have to play with the handle for about 5 minutes before I'm confident I've got it right, before I put it all back together.