If you mean "update" in RealEstateManager :: Settings - Administrator Settings - Update Options - this button for Update component, before use it look our documentation.
Before make any upgrades, please make the backup of your website and database.
Full save so files and folders:
Please do full dataBase backup.
Then go to [realestatemanager] [Settings Backend] and set [Update] to “YES”
The uninstall component and install new.
Your customized changes are available only for your version, if you will make update you will lose it!!!