Fatal Error: Problem Adding Second Custom Post Type to Functions.php

I’m working on a client site and making edits – I copied and pasted exactly the same code for as the first one (and forgot to rename) and have now received this fatal error and can no longer access the WP-admin panel:

Fatal error: Cannot redeclare custom_post_type() (previously declared in /home/XXXXX/public_html/wp-content/themes/concierge/functions.php:45) in /home/XXXX/public_html/wp-content/themes/concierge/functions.php on line 183

The “XXXXX” are in place for privacy reasons.

I know I need to go back in and update as I can’t reuse the same function name. However, this is a custom theme, and I need to know HOW can I get back the WP-admin and remove the second post code to restore the site back to its previous state? HELP!