Create your Light's Vengeance account at the link above and activate it via the email confirmation link. Make sure you also check your spam folder, as some don't appreciate our emails much.

Download The Burning Crusade 2.4.3 WoW client if you do not have one. Mirror 1 Mirror 2 The archive password is: LightsVengeance Mirror 3 (Windows Only Installer, Multi-Language Support)

Modify realmlist.wtf to: set realmlist logon.lightsvengeance.com

Open your WoW client and log on from the client with your registered Light's Vengeance account credentials.

For extra security, you can enable 2 Factor Authentication (2FA) in your account settings on the website. Once 2FA is enabled, you will be prompted for the code each time you login to the game.