The article is for X-Cart 5.2.x only. But there is another article that explains how to migrate 5.2.x modules to 5.3.x:
http://devs.x-cart.com/en/migration_guides/updating_modules_from_5.2_to_5.3_branch.html
In X-Cart 5 there are no SQL patches. Everything is done via editing Model classes and re-deploying the site (the re-deploy process will adjust the table structure).