Remove Custom Fields in Frontend and Admin in Magento (so I can install an extension)

I had some custom fields added to my checkout process and customer entry in magento admin that I'd like to remove. I have two Magento extensions I'd like to install and I think these customizations are causing errors. I just need 9 custom fields removed from frontend and backend so I can install these extensions. I'll install the extensions, just need the custom fields removed.