Its actually pretty easy, I'd make sure you have a backup of your repo first.
git filter-branch --env-filter 'if [ $GIT_AUTHOR_EMAIL = paul@hit-nxdomain.opendns.com ]; then GIT_AUTHOR_EMAIL=paulsidekick@gmail.com; fi; export GIT_AUTHOR_EMAIL'
git filter-branch -f --env-filter 'if [ $GIT_AUTHOR_NAME = "paul" ]; then GIT_AUTHOR_NAME ="Visco, Paul"; fi; export GIT_AUTHOR_NAME'
Ditto.... I kinda wish I was a tech geek sometimes. But then I just love being all about beauty products...
Waay cool! :)