Use a knife to cut through the tail bone at the vent. Then use the knife to make two inch and a half cuts at a 45 degree angle from the initial cut up the belly. Hold the tail with your foot and pull with the back legs and strip skin all the way down to head and front legs. The skin tears at the belly due to the two small cuts. Grab this belly hide while still holding foot on tail and skin out the back legs. Without releasing my hold on the tail or the skin from the back legs I take my game shears and cut off the front feet and head and holding the squirrel over a bucket of water I cut both back feet off allowing it to drop in the bucket without even touching it minimizing hair on the squirrel. This is very fast and efficient.
An old timer taught me to get two - five gallon buckets and fill them with water . When you skin the squirrels put all ungutted squirrels in the first bucket, then as you gut them put them in the second bucket. Most all the hair and blood comes off in this process and the meat is cleaner and easier to work with.
I collect old sq. calls and in several of the calls dated from 30s and 40s, the method described above is called the Cherokee method. Except in Herter,s wooden calls with metal strikers, they have printed literature and they call this the Sioux method. Either way this is the fastest and cleanest method for me.