Plugin redirection – redirected website to wrong one

Hi,
I made a big mistake and I have no idea how to fix it.
After installing “Redirection” I redirected the .com website to .org (I have both domains on strato).
Unfortunately that was the second step before doing the first.

Now I cannot even log into wp at all (The requested URL was not found on this server) becuase he redirects me to .org which doesn´t exist.

How can I delete the plugin redirection without having access to wp?!

I reinstalled a backup on strato from before the change – not the WP backup (did not make a back up yet – 2nd mistake).

What can I do to get access to my wp site???

I need help as it is a charity website…thanks very much!

The page I need help with: [log in to see the link]