Restore WordPress Admin Email Access

My WordPress site is up and running, but the administrator email tied to it was linked to an account that has since been hacked. I still control the hosting environment, cPanel, phpMyAdmin, SSH, everything, but I have not attempted any recovery steps yet. I’d prefer to leave this to someone who knows the safest and fastest procedure.
What I need from you:
-Update the primary administrator email in WordPress and confirm the system fully recognises the change (password-reset flow, notifications, site admin email, etc.).
-Provide a short note explaining exactly what was done so I can reproduce it if needed in the future.

If the fix requires editing wp_users in phpMyAdmin, adding a temporary snippet in functions.php, or using WP-CLI, that is perfectly fine—please choose whichever method is the cleanest and least disruptive.
-Once the new email address is set and confirmed working, please carry out the following security checks to ensure the site is fully safe again:
-Verify there are no remaining references to the old compromised email anywhere in the WordPress back-end (General Settings, Users table, plugin settings, theme options, SMTP plugins, etc.).
-Review all WordPress user accounts and remove or correct anything suspicious (unknown admins, changed roles, unexpected capabilities).
-Check for malicious plugins, modified core files, or recently altered files—especially in /wp-admin/, /wp-includes/, and /wp-content/.
-Confirm that no unauthorised code was added to functions.php, wp-config.php, or in Mu-plugins.
-Ensure plugins and themes are up to date and that no abandoned or high-risk pluggins remain enabled.
-Review server-level access: check recent FTP/SSH/cPanel logins, remove any unknown access keys or users, and confirm password resets have been applied.
-Verify that the site’s email sending configuraton (SMTP or PHP mail) is clean and not redirecting or logging emails to unauthorized destinations.
-Run a final security scan or integrity check to confirm the installation is clean.
-After completing all steps, please send me a concise summary of everything you changed or verified, so I have a complete record.
-A second specilaist will scan the new result in search of any further suspicious code or element.

I’m ready to provide immediate server access as soon we reach agreement. Looking forward to getting this resolved quickly.