Restore Original WooCommerce Checkout Page

Hi guys, I have a simple problem.
Im working on this website, And i needed to include custom Checkout Fields in the Ceckout page, So i edited the Functions.php and coded the new fields in.

Assuming all was well i deleted the backup that i had to find out that that the fields didnt show up on the order details. Which i couldn’t seem to fix. So i found a plugin that has only just been released to set custom fields in the checkout page. But there seems to be a problem with the Jquery when trying to add new fields via the plugin. I seem to be the only one with this problem and right now im trying to troubleshoot whats causing this. So after trying everything i could think of. It came to my attention that it might be because the Functions.php file was edited and its conflicting with the plugin. So i want to restore the code that was inserted by woocommerce when it installed. But i dont want to take the risk of uninstalling it and re installing it to find that all my products are gone. So im in a bit of a pickle and scratching my head over how i can do this the simplest way. Thanks 🙂