The process for upgrading AllEvents to latest version is the same with new installation. Please note that:
Is it necessary to uninstall before performing an update? It's not recommanded. Uninstalling will delete all information in the database as well as the AllEvents files. You will lose Configuration & Menus if you choose to uninstall. The AllEvents data will not be deleted in database.
Will the update remove my existing data? No, if you perform the update by installing the component over your current installation, all your data and settings will be kept intact. The update will simply bring up to date the database and other files that are part of the new version.
Will the update override the source code adjustments I've made to AllEvents? Yes, if you've edited any AllEvents files (this includes .php, .css and .js files) they will be overridden by the update. If you did perform source code adjustments to AllEvents, please make a note of the changes you've made and re-do them after the update is performed.