Brion Stoutarm and Adarkar Valkyrie do not have summoning sickness.
You control a creature that can tap to produce at least ({R} magic symbol) .
Steps
Activate Adarkar Valkyrie by tapping it, targeting Village Bell-Ringer.
Activate a creature you control by tapping it, adding at least ({R} magic symbol) .
Activate Brion Stoutarm by paying ({R} magic symbol) , tapping it and sacrificing Village Bell-Ringer.
When Village Bell-Ringer dies, Adarkar Valkyrie triggers, returning Village Bell-Ringer to the battlefield from your graveyard.
When Village Bell-Ringer enters the battlefield, it triggers, untapping all creatures you control.
Resolve the Brion Stoutarm ability from step 3, dealing damage equal to Village Bell-Ringer's power to an opponent and causing you to gain that much life.