1. Make a complete site files backup with your favorite FTP client or backup software.
2. Create a backup copy of your Joomla site database.
Only after these important steps, you can now safely update the module to the latest version.
No need to delete the already installed module because the new module version automatically replaces the old files.
The update procedure is the same as installation. So in Joomla administration panel you go to Extensions > Extension Manager > Install.
Then open tab "Upload Package File" select the file you got from us and press the button "Upload & Install".
If installation succeeds, you should see this message:
"Installing module was successful."