New version 5.1 not able to log in after site have been hacked

Hi, 3 days ago I have updated my website to the newest version 5.1 and yesterday the site was hacked by a MySql injection. The table wp_users was filled by more than 500 users and the real uses were overwritten by junk. I have cleaned the table and reset the real users, i have generated a new hash with the admin password but I am afraid this new version uses a new password hash which I can’t find on the internet. So now I am stuck and don’t know anymore what do to access my admin area.
Thank you in advance.

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