XenForo admin area isn’t inside a directory but is accessible via the admin.php file. So one can’t add htaccess based password protection to a directory
Password
How to Reset a XenForo Password from phpMyAdmin
If you have lost access to email, there are many ways to reset the password using phpMyAdmin. Here are a couple of really simple ways to reset it.
Forgot your Password? How to Recover a Lost Password in XenForo
Forgot your XenForo password? Don’t worry. This step by step guide will show you how to recover a lost password in XenForo. Works for admins and members.