First of all I would never run a game that allowed feats, and even if I did, I would never allow the obscenely overpowered variant human. That solves most of your dilemma right there.
If I did find myself in that situation, as the DM, the only reasonable way to rule it is ad hoc. Keep the languages, skills, and feats. Subtract out the old racial bonuses, add in the new ones, and if it goes over 20 then just cut it off. If the character somehow "loses" two points from their high stat, then that's the risk associated with the spell; it's their fault for having died, and the caster's fault for not casting a real resurrection spell.