Login / access issues

I have been given the task of re-designing our company’s website, and have a class A problem – I cannot access the wordpress account/host/database/server.

The website in question was built very long ago, by a person no longer working in the office, hence the email with which the account was made no longer exist.

I have tried to access the website server, database and host, however can not locate and/or access either, as the usernames and passwords I have been given do not work on any of them.

There is also no WordPress files on our internal server, so the emergency password reboot (with emergency.php file) does not work, as I assume the files needs to be linked to the website for this to work (I have tried downloading WordPress and copy it in there, but it doesn’t work, as expected).

Does anyone have any advise as to how I can reset the password, with access to the website/login page only, without using the reset password button (as I can’t access the email the new password would be sent to)?

I guess it’s worth noting that I’m new to wordpress and would therefore be using the latest version once I get started, however without access to anything I’ve not been able to explore it properly.

Any help would be so very much appreciated !