On the remote, you would use the "TV/Video" button to get out of AV mode and back to TV/Ant viewing.
If you need further assistance, let me know.
There are no controls on the TV that will perform this command. You will at least need a basic Universal remote in order to get the TV off of AV mode. You can purchase one at the link below that will operate your Samsung:
I realize that you don't have one, that is why I posted a link for you to purchase one.
There is no other way to get the TV off of AV mode without a remote of some sort.