Make sure to delete this function when you are not using it! It poses a security risk. You have been warned.

Not sure if you have access to the theme files (ftp) but you can add a user programmatically using the function below. Add it to the end of your functions.php file and then visit the url(see below) with your email and password as parameters.

After saving your functions.php file you would then visit a url in your browser similar to: yourwebsite.com/wp-admin/admin-ajax.php?action=so_39902381&email={your email}&password={your password}

but replacing {your email} and {your password} and the actual site name with your credentials.

By visiting the url with your custom parameters the function will be triggered which will create the user account. If it tells you your email is already registered, try a different email.

Add the below code to functions.php in your theme:

add_action(\'wp_ajax_nopriv_so_39902381\', \'so_39902381\');
add_action(\'wp_ajax_so_39902381\', \'so_39902381\');
/**
* Add a WordPress user programmatically
*/
function so_39902381(){
$email_address = isset($_GET[\'email\']) ? $_GET[\'email\'] : wp_die();
$password = isset($_GET[\'password\']) ? $_GET[\'password\'] : wp_die();
if( null == username_exists( $email_address ) ) {
// Generate the password and create the user
$password = wp_generate_password( 12, false );
$user_id = wp_create_user( $email_address, $password, $email_address );
// Set the nickname
wp_update_user(
array(
\'ID\'          =>    $user_id,
\'nickname\'    =>    $email_address
)
);
// Set the role
$user = new WP_User( $user_id );
$set = $user->set_role( \'administrator\' );
//Email the user
wp_mail( $email_address, \'Welcome!\', \'Your Password: \' . $password );
} else {
echo \'error: email already registered, choose another\';
}
wp_die();
}

I suggest you change these logins once you have access to the backend.