If you are trying to connect your DVD player to your STB instead of TV (say you don't have enough connections on your TV for both STB and DVD player), you can't.
STB does not have a pass through mode.
If your reason for wanting to do that is a shortage of inputs on your TV, you can buy a splitter which will solve that problem. Amazon carries them and they are relatively cheap. I've used a 3:1 HDMI splitter and it worked well.
