How to change the password for phpMyAdmin?

Can you run queries on your database? IF so you can do it using the built in Mysql commands.

SET PASSWORD FOR 'username'@'%' = PASSWORD('newpass');

You will have to change the username part (to probably pma) and the % part (to probably localhost).

So it becomes:

SET PASSWORD FOR 'pma'@'localhost' = PASSWORD('newpass');

For information on the SET PASSWORD command see: dev.mysql.com/doc/refman/5.0/en/set-password.html

To see exactly what user and domain (the localhost/% part) your account is using do:

SELECT User, Host FROM mysql.user;

That should show you all your mysql user accounts. Look for the one that looks like it's for PHPMyAdmin (probably pma).