I just happened to lock myself out of MySQL, but luckily I have root access to the server so I can reset it easily by first shutting down MySQL:
```bash
/etc/init.d/mysql stop
```
And then creating a MySQL init file with the desired password:
```bash
$ echo "SET PASSWORD FOR 'root'@'localhost' = PASSWORD('1234');" >> /tmp/mysql_init.txt
```
Starting MySQL with the **--init-file** parameter like this resets the password:
```bash
$ mysqld_safe --init-file=/tmp/mysql_init.txt
```
Remember to delete the file:
```bash
rm /tmp/mysql_init.txt
```