1. You're going to need to get a microfiber cloth. If you don't have a microfiber cloth, you can use any kind of soft cloth to use instead. Microfiber is highly recommended though, so you don't scratch the screen on your TV or computer screen.
2. Next you will need toothpaste. You can use colgate, or really most brands will work. You want a paste without gel. For some reason the paste has a better cleaning agent when it comes to permanent markers.
3. Dampen your cloth with a little bit of water, and add a pea size amount of toothpaste. Lightly smear it around the cloth.
4. In small circles wipe the screen with the toothpaste on it to remove it. As soon as it's removed use a clean part of the cloth to continue wiping off the toothpaste from the screen.
5. Rinse the cloth well, and wipe over the area.
6. Next spray down the screen with an electronics surface cleaner. Make sure it's safe for your screen an monitor.