1- Remove existing checkout module.
2- Install a new checkout extension ( already purchased and have the files of the new extension)
3- Fix any issue related to the new checkout extension and ensure it's 100% working.
4- Ensure the payment methods of (Paypal, Mastercard, Visa and Cash on delivery) are 100% working.
5- Customize the colors of the checkout page to match with the CSS colors of the website.
6- Ensure that (English/Arabic) checkout page layouts are 100% responsive.