brew unlink git-bpf-init # Only applies if you've installed via homebrew.
rm -rf ~/.ab-git-scripts
rm -rf .git/rr-cache # You will lose any resolutions that haven't been sync'ed with the remote.
rm .git/ab-git-scripts
rm .git/hooks/post-commit
rm .git/hooks/post-merge
gem install git_bpf # will need to use `sudo` if using OSX system version of ruby.
git-bpf-init
git-bpf-init <path/to/project/repository>
i had to "sudo gem install git_bpf"