I stumbled upon this question http://serverfault.com/questions/12373/how-do-i-edit-gits-history-to-correct-an-incorrect-email-address-name from google and was surprised to find it here on SF. 
I did notice it's very old (5 years) so just out of curiosity, was it not off-topic *then* or is it not off-topic even now? If it is, should it be migrated to SO?