You must go to your paypal account and recreate all the “Buy now” buttons. Also, you need to create a “view cart” button. When that is done, replace the code for the buttons on your website with you own codes and update your web page.
1- Login to paypal
2- click on “Tools” in the top menu
3- then click on paypal buttons
4- create your buttons
5- copy/paste all your codes to a text file or .doc file then update your products page.
*If your website is on a wordpress template, use the “email code” to insert your “buy now” buttons on your webpage