Use a cotton swab with isopropyl alcohol-use it only where needed as it also removes the clear protective top coat that is there to protect.
Rich aloe cleaner and conditioner on my wheelskins wheel cover and I am constantly amazed by the results. The cover is white leather http://www.meguiars.com/?home-leather-care/Gold-Class-Rich-Leather-Aloe-Cleanerread the infor on it.
Hairspray removes ink from fabric. Test it on something other than the car seat or on a part that is not showing. Spray the spot then blot it with a dry cloth.
Westley’s upholstery cleaner work great. Did the exact same thing a few years back. This product took it out completely, which I was very grateful about because I was borrowing my wife's grandmother's Caddy at the time.