If the writing you put on yourself won't come off, for whatever reason, then follow these steps:
Step 1: Try using dish soap since it is designed to remove grease and some markers use grease in their ink.
Step 2: If sStep 1 didn't work, then use rubbing alcohol. Note: Rubbing alcohol will dry your skin out, but it will even get "permanent" marker off your skin.
Step 3: If you had to resort to Step 2, then get on cam and rub lotion all over your body!