How to add/remove shipping countries from checkout page

To edit the countries you do or do not ship to, navigate to Setup -> System Screens. It will be at the very bottom under Admin.

Next, you will need to click on Show Rows. Select 100 from the drop down so it shows all of the options. The second option from the bottom will display "include_countries." Click on it.

From here, carefully navigate which countries you want removed. You can remove as many countries as you'd like. Use the backspace to remove any countries and click Save at the bottom of the screen. 

Important: In order for the changes to take affect you need to contact your dedicated Account Manager who can have it reflected on your checkout page.