CONNECTION GUIDE / HOW TO PLAY ON THE WOW CLASSIC
Download the ClientFull 1.12 Client [Mega.nz]
You don't have to download the client if you already have a 1.12 client there is no difference in this client and the one that you have if it is a 1.12 - 1.13 client.
You cannot use the CLASSIC Client from Blizzard as you cannot modify the realmlist using that client.
The realmlist.wtf file is located in the main World of Warcraft directory: \World of Warcraft\realmlist.wtf!
You must delete everything in the file and add the our realmlist.
Please use the following realmlist:
set realmlist logon.wowtheclassic.com