You should try a MR. Clean Magic Eraser. My two year old grand daughter got a Sharpie one day off my desk and wrote on a lot of different things. I used a magic eraser and it took the marker off of everything. Even my bed comforter! Now I always keep them in my cleaning supplies.
Mr. Clean Pads .... They work great!
Nail polish remover! Its epic! Try it first :d!!!
Try hand sanitizer
Just go over the permanent marker with an erasable whiteboard marker and it should come off like magic- always works!!!
Try WD40 and see if that will take it off.
Using a Pencil eraser on permanent marker works on a lot of surfaces.
Alcohol works as a solvent for most permanent inks. Try it with the Magic Eraser.
You're not going to believe this but I just used Crest Pro Health Tooth past and MR. Clean Magic Eraser.
Rubbing alcohol; just use a cotton ball, put rubbing alcohol on it and wipe the permanent marker off. I don't add anything to it, it does a great job and is fast.