How to remove payment gateway?

Open your form in the Form Builder and select the Payment field. After that, click the Trash icon to remove the Payment field.

Here's a screen animation guide:

Let us know if you need further assistance. Thank you.

John,

Thank you for the reply. If I do delete the field, it will delete all of the products I added.

Yes, it will also be deleted. If you add another Payment field after removing the previous payment field the products will be added again to your form. Here's a screen animation of my explanation:

If you would like to sell your products or collect amounts and process the payment offline through check or wire transfer, use the purchase order tool. Please follow this guide: 

https://www.jotform.com/help/460-How-to-Create-Payment-Form-with-Purchase-Order