With the skin removed, turn attention to details of cleaning away leg, wing, and tail muscles, removing eyes, brain, and jaw muscles from skull and scraping out whatever fat is in the skin.
To clean leg bones, skin out the thick, meaty shins, using thumb nail and scalpel to aid where necessary, down to heel joint or upper end of tarsus. Just above this joint sever the tendons, front and back, and peel leg muscles off.
In owls skin on down the tarsus to as near foot, or toes, as possible and clean out tarsus muscles.
In large birds, next split ball of foot, insert point of a steel spindle under base of tarsus tendons beside hind toe and draw these cords out. This will sometimes require a strong pull.
Always do this after the leg above has been cleaned. In small birds it is not necessary to split ball of foot nor to remove these tendons.
Next remove the wing muscles. Peel skin down to elbow. Cut tendons free just above elbow and strip muscles off. To clean forearm in a small bird, use the thumb nail to shove skin forward toward wrist, on front of wing, without breaking union of large, secondary flight feathers with wing bone.
With scalpel cut and lift out elbow ends of forearm muscles, strip them out down to as near wrist as possible and cut off.
In a large bird, split skin of forearm and hand along under side after carefully separating feathers over bare strips of skin. Peel skin back both ways and remove flesh neatly. Scrape out whatever flesh is in evidence on hand bones in same way. In a bird with no fat adhering to the skin, the skull and tail only remain to be cleaned in order to complete the skinning operation.
To clean skull, remove eyes with a scalpel, scrape brains out through cut-off skull base, and trim away jaw muscles and a portion of roof of mouth.
To clean tail, peel it out carefully and scrape and cut away fat and meat adhering to bone and base of quills.