My son was born 12/2000. I gave him a hyphenated last name of the person I thought it could be (actually is but rather not open pandoras box-he hasn't even tried to see him in almost 10yrs and not interested in him seeing him at all). That person's name is not on the birth certificate. How do I go about changing his last name to just mine? He was born in KY. Not sure if that makes a difference.