When resetting your Joomla password you may want to generate your own md5sum password.

I found an oddity with doing if from the command line. If you just echo the password

echo admin | md5sum
456b7016a916a4b178dd72b947c152b7  -

echo -n admin | md5sum
21232f297a57a5a743894a0e4a801fc3  -

Once you have your md5sum hash of the password you want. Login to the mysql client.

mysql -uroot -p

USE joomladbnamehere;
UPDATE jos_users SET password = '21232f297a57a5a743894a0e4a801fc3' where username = 'admin';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0