Restore WordPress Production Site

My production WordPress site stopped loading because the index.php file became corrupted and, unfortunately, I have no backup of that file. The good news is that I still have full access to an up-to-date staging/UAT environment where the entire site—primarily pages with text and images—runs perfectly.

I need someone who can quickly bring the live site back online by either repairing the damaged index.php or, if that proves faster, spinning up a fresh WordPress instance and cloning everything from staging to production (themes, plugins, database, media, settings). Whichever path you choose, the end result must be a stable production site that mirrors staging exactly, with all URLs and internal links functioning as before.

You will receive credentials for both environments as soon as we start. Please outline your preferred approach, estimated turnaround, and any tools you typically use for migrations or file recovery so I can grant the right access straight away.