Permanent marker on white pants

Paper towels beneath stain, pour rubbing alcohol on it, marks should transfer to paper towel. Be sure to have the paper towels thick enough that the marker does not end up on the other side of the pants. Rinse with cool water and launder.

You can try dry cleaner fluid.

https://www.youtube.com/watch?v=1YRjXz4dzcw

https://www.youtube.com/watch?v=zM-7Rx0ppZg

Hope this helps.

Place the stain face down on clean paper towels. Sponge rubbing alcohol into the area around the stain, and then apply it directly to the stain. Continue sponging the stain with alcohol, frequently changing the paper towels underneath, transferring as much ink as possible to the paper towels. Rinse thoroughly. Launder.

http://www.goodhousekeeping.com/home/cleaning/tips/a16037/stains-felt-marker-may07/