Just saw this on LinkedIn… Haven’t tested it, but looks workable.
The problem: lost WordPress administrator password and no way for WordPress to send e-mail, so the conventional password reset isn’t an option. However, direct access to the database (via phpMyAdmin or otherwise) is available.
The solution: a two-part hack.
Part one. Create an activation key manually:
UPDATE `wp_users` SET `user_activation_key` = '123456789' WHERE `user_login` = 'adminUserName';
(Obviously, wp_users and adminUserName must be replaced with the installation-specific values.)
Part two. Reset the password by going to the password reset page:
On further thought, the first step could be even simpler; even if WordPress was unable to send a password reset e-mail, it probably still created the activation key, so it could be looked up in the wp_users table, rather than written into it…