Removing and reinstalling MySQL on MacOS:

```
brew remove mysql
brew cleanup
sudo rm /usr/local/mysql
sudo rm -rf /usr/local/var/mysql
sudo rm -rf /usr/local/mysql*
sudo rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
sudo rm -rf /Library/StartupItems/MySQLCOM
sudo rm -rf /Library/PreferencePanes/My*
launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
```
edit /etc/hostconfig and remove the line MYSQLCOM=-YES-

```
rm -rf ~/Library/PreferencePanes/My*
sudo rm -rf /Library/Receipts/mysql*
sudo rm -rf /Library/Receipts/MySQL*
sudo rm -rf /private/var/db/receipts/*mysql*
```

Restart your computer to make sure that all the processes have been killed.

```
brew update
brew install mysql
unset TMPDIR
mysqld --initialize --user=`whoami` --basedir="$(brew --prefix mysql)" --datadir=/usr/local/var/mysql --tmpdir=/tmp
mysql.server start
```
Now run `mysql_secure_installation`

Finally, log into mysql with
```
mysql -uroot -p
```

Within mysql create users and grant permissions
```
CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON *.* TO 'username'@'localhost' IDENTIFIED BY 'password';
FLUSH PRIVILEGES;
```