I want to unlink Steam steam from mistake to link MS ID

I just make mistake I don't know It's can link I just Got BIG MISTAKE and now I need to Unlink Steam ID .I didn't create anycharacter yet ,PLEASe HELP ME!

If you went past the select ship screen, you're out of luck. Sorry to say, but you'll have to make a new Steam account if you want to link.

@FANtasyStarOnline Isn't joking either. It was made clear on the dialogue that appeared before ship selection the first time, not to mention on the steam announcement here on the news section of the website that going past that dialogue would make it impossible to properly link MS Account and steam.