Several places below reference running update.php. This means going to your yoursite.com/update.php after logging in as an administrator. If you are unable to log in, you can force access to update.php by editing the settings.php file in drupal/sites/yoursite/settings.php and set the following line to true (don't forget to change it back after updates are complete)
$update_free_access = FALSE; change to: $update_free_access = TRUE;