How to Edit WordPress With a Redirected Domain

1. Open the .htaccess file controlling the redirect on your server. It will be in the root folder.
2. Find the line that starts with 'RewriteRule.'

3. Add the following to the end of the line after the closing bracket: !^/wp-admin/
4. Save the .htaccess file. Now your main domain will remain redirected, but you can log into wp-admin and use all the WordPress controls as usual.