Summarize the following:
Don't bend too hard or the tag will crack in half and spill ink everywhere. This should loosen the pin and make it pop off.
Hold the security tag with the ink cartridge side up. Grip one of the sides of the rectangular tag with a pair of pliers. Grip the other side of the tag with a different pair of pliers. Gently bend each side of the tag down using the pliers. Keep bending until it pops open.