The skin is "sanded" to remove the epidermis and dermis
along with the ink. This is the oldest methods of tattoo removal
going back more than 5000 years and is based primarily on abrasion
with a metal tool. When used in combination with salt as a grit
it is sometimes called salabrasion. When the skin is frozen beforehand,
to reduce bleeding and pain, it is refered to as cryosurgery.
This is a painful procedure that can easily lead to scarring
or infection. In general it is not practiced nor recommended nowadays.