Locked Out Of Windows 8.1 Computer - MS Account Password Lost

Okay, so this the worst I've ever been locked out of a computer. There's an account on the computer that's been linked to a Microsoft account, however the MS account password is lost and since all the forgot password options have been filled in with gibberish there's really no way to recover it.

Normally I'd say just reinstall the OS, but apparently we need access to this account.

There's no other user accounts whatsoever. Just one administrator account.

So, facts:

- It's linked to Microsoft.
- Microsoft account in inaccessible.
- Microsoft account cannot be recovered.
- There's no backups or anything.
- Computer account needs to be accessed unharmed.

Ultimately, I guess we need to actually hack into this account by force and I honestly don't know how to do something going that far because I've never been forced to go that far before. I'm going to guess it's going to involve booting from a pendrive or something.