To remove iron on letters from a fabric, dip a cotton pad in alcohol and rub it on the back of the shirt, right behind the iron-on letter. After about 10 seconds, try to peel the letter off and rub the last stubborn pieces off with a wire. Wash the shirt in hot water and scrub it with a brush. If these methods do not work, apply the iron method. Wet the shirt and put it face up with a piece of parchment on top. Put your iron on the cotton setting and rub it in circles over the parchment. Lastly, peel off the parchment.