Hi, Willikenn! To open PiP, from Live TV, press the Options button. This will give you the ability to select PiP On/Off on the Hopper. You can change the channel of bigger screen by entering the desired channel. If you need to change the other picture's channel, press the Input button on the left side of the remote. This will switch which picture is the main picture and allow you to enter the channel you'd prefer.
If you have a different remote model, you'll have a PiP button at the bottom of the remote instead of pressing the Options button to select PiP.
You can find step-by-step instructions online at https://www.mydish.com/support/products/hopper/how-to/manage/live-tv