Please use the official recovery form at https://account.live.com/acsr and provide all details you remember, including:
Your last used password
Recovery email or phone linked to the account
Any recent emails or account activity
Microsoft will review your submission and guide you to regain access. Reinstalling the app will not bypass security or delete emails stored on Microsoft servers. Microsoft cannot take control of accounts directly, so completing the recovery form is the only way to restore access.