Slider came apart, how do I put it back together?

My son was wrestling with his Brightside in his pocket and managed somehow to separate the sliding keyboard from the rest of the phone. I can't quite figure out how to put it back together. There is a ribbon cable which I am guessing I can just slide back into the other end that's under the tape. But there's a firm little piece of metal that I'm sure affixes to something, but I can't figure out exactly what..?

Any help appreciated!