>>718095141
How about
1. Link your account only on Nexon's site (if you want to save your progress
2. fully delete the game (check appdata, steam folders and other paths if there's anything saved)
3. re-download the game and it SHOULD give you a default/steam account.
If you don't care about saving any progress made just click on "delete account" (still on the main screen). There are also other options in-game, on the account's tab.