i tried to reset my password for my admin account, but reCaptcha is broken, so it doesn't work. Is there a way to disable Captcha in database or files? Or delete password in database?
Can you define "broken"? I'm not positive how the old ReCAPTCHA behaves now that it's shutdown -- it may appear to be broken but submissions may always pass. (If it returns an unexpected response, we generally allow that through.)
Otherwise, you're probably really looking at file edits to force the result of XenForo_Captcha_ReCaptcha::isValid() to return true.