The easiest method of removing a temporary tattoo is with baby oil. A dab of baby oil on a cotton ball is typically sufficient to start breaking up the glue and ink in the tattoo so it can be rubbed away easily. Most temporary tattoos are made with a combination of ink and glue, and removing them usually requires common household products that are in most people's medicine cabinets.
For tougher tattoos, allowing the oil to remain on the tattoo for a few minutes may be necessary. If that doesn't work, soap and water applied with a vigorous scrubbing motion using a washcloth may be required. Temporary tattoos may be a bit difficult to remove, but with a little work, they will come right off.