Upgrading all depends on the build you're working on. If you've followed Tonymacx86's customac guides, you're probably safe downloading and updating like any other legitimate mac. It varies from person to person because there are so many variations of hackintoshes and components but the golden rule is always to make sure you make a back up, and/or clone your working build. If you have any doubt, I'd wait to see whether others are successful first.