I think you would have to get a new nut to raise them. which the nut it's self isn't that much I thing, but you would have to take the old one off and try to screw up the fret board or neck. Or you could look into finding someone that lives close to you, or works in your town that does it, I'm sure a Luithier, not a guy from Guitar Center, but a Real one 
should be able to do it and make it professional
should be able to do it and make it professional
