If you were real careful with a razor blade you could probably get them off without hurting the board. Use some goo gone if there was stickiness left over (I dont think that would hurt the board?) Hopefully the sun hasn't faded the board too much or else the stickers will still show even when they are gone.
Herbert... Glad to see you got the board ok. Hairdryer idea sounds best to me. After that, there is a product called "goof off" that works pretty killer on the leftover residue. I don't know if they have it over in Hong Kong though.