1) At first we need account for Blade and Soul KR. Unfortunately we can not register any account by ourselves because it requires proof of Korean passport by mobile phone or credit card. Therefore we need to buy Korean account.There are many shops where you can buy an account, but I recommend this one (or you can find any korean who can register account for you).
2) Open the Official Korean Blade and Soul gold site
3) Login with your ID and password
4) Click this link
5) Click any of this 4 red buttons, then confirm the rules and load the downloader
6) Open this file and wait for the server connection (if you will see some error just close it and try again)
7) Start to download the game client. Another way u can download this torrent file (as for me torrent speed is much better then from korean web site)
8) After download is finished open Setup.exe. In the installer always click Next (you can see it on the pictures)
9) When you finish the installation, you blade soul gold need to go back to korean official web site and login again with ur ID and password and click the red button above ur profile
10) Now you can see Blade and Soul KR launcher. Click the blue button. It will update your game client to the latest version
11) Welcome to the world of Blade and Soul!