ArcheAge: Unchained will change Publishers from Gamigo to Kakao Games!
So you have the Option to Transfer your Game Account. For more Information check the links on the bottom of this guide.

Here is the link to the video guide (should be embedded on the bottom of this guide!):
https://youtu.be/MDC92qYEwAU

Lets start with the written one:
How To Transfer
To transfer, follow this simple step-by-step guide on the process:

1) Go to this website and log in with your Glyph account.
https://glyph.trionworlds.com/account/profile/manage-game!input.action?dd=1&request_locale=en_US
2) Copy the Game Data Transfer code by highlighting the text and clicking “Ctrl+C” OR by clicking the “Copy to Clipboard” button.
This will be under Account-Linking (click on the "Account" tab)
3) On November 19, navigate to the Transfer page by Kakao Games.
https://archeage.playkakaogames.com/transfer?lang=en
4) Sign up for a new Kakao Games account if you don’t have one already.
5) Log in to your Kakao Games account.
https://login.playkakaogames.com/login
6) Follow the steps on the Kakao Games transfer page and apply the transfer code
7) You’re done!

Sauce:
ArcheAge: Unchained will have a subscription model (you will get a lot of free sub time) and there will be changes to the ArchePass
https://archeage.playkakaogames.com/news/518

General Information about the transfer process and a FAQ from Kakao Games
https://archeage.playkakaogames.com/news/521

Glyph Store Closure and How To Transfer
https://www.trionworlds.com/archeage/en/2021/11/18/store-closure/

FAQ: Game Data Transfer from Glyph/Gamigo forums
http://forums.archeagegame.com/showthread.php?364799