Friend lost pin to old account, and cannot unlink it from steam

So basically, I just recently got back into 9D for nostalgia sake, and my friend decided to get back in too, however his steam account was already linked to his years-old 9D account, and he no longer knows the pin, he already tried 3 times I think so he got locked out.
He doesn't necessarily want his old account back, he just wants to start a new fresh one, but there seems to be no such option as it automatically logs back into the old account
Is there any way for him to just unlink the old account from steam and make a new one? (preferably without having to wait several days for support) Like maybe delete or change a file or something to make it start fresh?

 

Afaik you can't unlink your steam account simce it auto logs through steam. You have to eithet use the offical client and make a new account or make a new steam account to play through steam.

 

Hm, so if he downloads the official client and makes a new account, will that then not automatically open steam and switch to that account? Or will it link his new account to his steam instead of the old account?

I was really hoping there would be an easier solution, I really don't understand why there wouldn't simply be a reset option since it has an email linked.
Imagine downloading the game once to try it, and then having to remember the pin for the rest of your life even when playing it once, just in case you'll ever want to download it again in the future, or keep making new steam accounts seems strange

 

So little update, apparently after a few more tries the steam 9D gameclient itself automatically opened a korean page in the browser and asked him for his user id for verification (neither of us speaks korean so our google translations could be off a bit), but essentially it's now asking him to select a phone carrier he is using, "sk telecom", "kt telecom", "LGU+", and "cheap phone telecom?" to verify his identity, however all those phone carriers are (from what I can tell) South Korean, whereas he is in Italy so he's not using any of those, not only that but he says he never gave his phonenumber for registration in the first place
In the attachment is what it prompts (google translated), look very dodgy to me to be honest

 

Hey there @Enschede2.

If you haven't already done so, can you get your friend to submit a ticket through the help desk?

In some instances, support may be able to unlink the account from Steam and/or reset the pin associated with the account.

 

I will tell him, thanks
Is that submitting a ticket in the support section on this forum? That support button at the top?

 

The official launcher is separate from the steam tied account, so you can change log in at will without having to make a new steam account. But you can't launch the game through steam.