Create authors.txt with a mapping from svn users to git users:
jane.doe = Jane Doe <[email protected]>
john.smith = John Smith <[email protected]>
Clone the svn repo using git svn:
git svn clone -A authors.txt svn://repo.site.foo/project/trunk project-git
Add git remote and push:
cd project-git
git remote add [email protected]:user/project
git push -u origin master
More details in the git svn documentation