Summarize this article in one sentence.
Take the garment off and bring it to the sink. Hold it so that the entire stain is visible. Turn over the garment so that the back side of the stain is under the faucet. It's essential to wet the stain right after it happens. Flush cold water over the shirt making sure that the stain gets completely wet. The pressure of the water should loosen the particles of the tanner so that they get washed away.  Do not rub at the stain as you are washing it. This will only make the stain stick more to the shirt. If the pressure of the water has not fully removed the stain, try using club soda. Pour club soda or seltzer over a cloth or towel. You don’t want to drench the cloth, but it should be more than a few drops. If you have a very big stain, use more club soda. If you don’t have club soda or seltzer in your home, you can also use water. Your garment is likely wet at this point from the water, but you will want to put something under the stain. You will be pressing on the stain, so putting a towel underneath it will stop it from spreading. If it is a garment like a scarf that you can lay flat, you do not need to put anything under the stain as long as you are sure that the stain isn’t touching any other portion of the fabric. Taking the cloth you poured club soda on, dab gently at the self-tanner stain. Do not rub or scrub at the stain; this will only make the stain more ingrained in the fabric. Instead, try to dab at the fabric, focusing on the heaviest area of the stain. If you see that the stain is removed, launder your garment as you usually do. If the stain is still visible, do not put the clothing item in the dryer. The heat from the dryer will make the stain set. Instead, wring out any excess water and hang the shirt up to dry.  Make sure not to hang the piece of clothing out in the sun. The sun's heat can also make the stain set into the garment.

Summary:
Position the garment. Run cold water over your shirt. Wet a cloth or towel with club soda. Place a towel or cloth underneath the stain. Dab at the stain. Dry your garment.