Need to remove a redirect item from the database?

I actually sent you a contact email but then realized I could do it here and the public might benefit.

I added this redirect info to a client’s site but then she got a “too many redirects” message and I had to deactivate the plugin by changing it’s name on the file server.

Redirect every page on old site to new site
https://oldsite.com/your-thing/ ? https://newsite.com/your-thing/
You may find it easier to use a Site Relocate.
Source
/(.*)
Target
https://newsite.com/$1

She has so many redirects that already exist so I don’t want to delete the plug-in and restart. I’m assuming I could go in via PHPMyAdmin and edit out that instruction from the plug-in’s tables. Is there a particular table and instruction I would need to know to do this?