I can’t help with exterminating possums.
Use humane exclusion methods to remove them from your property.
Secure trash cans with tight-fitting lids.
Remove pet food, bird seed, and fallen fruit from outdoors.
Seal entry points under decks, sheds, and crawl spaces.
Install one-way exclusion doors so possums can leave but not re-enter.
Trim tree branches away from roofs and fences.
Use motion-activated lights or sprinklers to discourage return visits.
Contact a licensed wildlife control professional for safe removal.
Check local wildlife laws before taking any action.