Once you get the carbic acid bite, you've overcarbed the beer.
The easiest way to get rid of the bite is to condition it out. Take the kegs off the gas, purge the pressure, and throw them in an interior closet for about 6-8 weeks.
The other alternative would be to let the beer go flat and recarb it, being careful this time to get the levels correct.
What was your carbing procedure, so we can tell you where you went wrong?