Uninstall first if needed
brew remove mysql
brew cleanup
launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
sudo rm -rf /usr/local/var/mysql
Install
brew install mysql
mysqld --initialize --explicit_defaults_for_timestamp
mysql.server start # no sudo!
Another good guide here
Useful commands
brew services start mysql
brew services stop mysql
brew services restart mysql