menu/settings/solo/duo mode....or press the mode button on the receiver.
I have no clue why they disabled TV2 since that is one of the best things about the 722k.
Sling is fine for remote viewing, but to be honest, I could care less to use it in the house when I have perfectly fine tvs in it.
You can buy more Dish 32.0 remotes from Dish for $19.95, resonable price but there is the $15 shipping!