Down shift to come to a stop

Well the trans is not set up to be a trans brake.

You can however slow yourself down with the trans by down shifting as you are slowing down, more in the case you are in an emergency. Just pull the gear shifter down one gear at a time.

Some trans you can do upgrades too that allow you to change gears or in some case mandate that you must change the gears yourself.

You will not be able to come to a complete stop by trans alone. Do not put it in park to stop this will break your transmission.