Soak feet in warm water for a few minutes then dip feet and vegetable oil slather on Vaseline by hand done quarantine the chicken in a cage with food and water and pine shavings for the bedding
No need to quarantine if the bird is already a member of a flock. Most likely the other birds have already been exposed and need to be treated as well. I skip the soaking and oil, just coat feet and legs in something greasy like vaseline (petroleum jelly) and repeat five days later to kill any that have hatched out. This suffocates them.