Step 1: Go to ftp://ftp.himeuta.com
and login via username:
and password: grandchase

Step 2: Click in Korean Voice Mod and find the file [BulletBuster]NA Grand Chase Korean Voiceover v0.99a.exe. (Don't delete this file after you're done installing the korean voiceover)

Step 3: Click on it, and you should download it. Save it in your preferred directory (desktop etc etc or anywhere you'd like).

Step 4: Run the exe. Press Next to continue and follow the instructions.

Step 5: Once done with installation, press Finish.

Step 6: Go to your Grand Chase folder (It's either C:\Ntreev\Grand Chase or C:\SG Interactive\Grand Chase, depending when you'd installed it, and those are only default directories).

Step 7: Find the exe called Korean Grand Chase.exe. Run it.

Step 8: Zomg. Korean voices.

***Tuesday***
Tuesday is the day of the maintenance. When you play after maintenance is over:

Step 1: Go to your Grand Chase folder (It's either C:\Ntreev\Grand Chase or C:\SG Interactive\Grand Chase, depending when you'd installed it, and those are only default directories).

Step 2: Find KV-Uninstall.exe.

Step 3: Uninstall the Korean voiceover mod using that executable mentioned in step 2.

Step 4: Run the Grand Chase normally and let it update.

Step 5: Once update is done and you're in the game, exit the game.

Step 6: Get your [BulletBuster]NA Grand Chase Korean Voiceover v0.99a.exe again (You shouldn't need to download this again if you didn't delete it)

Step 7: Run the installer again, and install the Korean voices.

Step 8: Run Korean Grand Chase.exe.

Note: You only do these 8 steps only one time after every maintenance. All the other instances, you only need to just run Korean Grand Chase.exe.