If you need to make any changes between normal updates there are a couple of ways to update and rebuild your HREFLang XML projects and XML site maps.
If the goal is to completely rebuild the project including importing all URLs from your source files and any recently added customer mapping then the RUN feature of Auto Update The system will reimport URLs from all the sources as well as any appended. This will completely rebuild the project. This is also the best method if you are using the auto-upload feature as this will rebuild and push the new version directly to the server.
This option will allow you to quickly regenerate the XML site maps using ONLY the current URLs in the system. This option should only be used if you have uploaded a new custom mapping table, manually deleted URLs from the database, and are not expecting any new URLs to be added to the system.