1) Uninstall the older version of EDIUS.
You can install EDIUS 9 to a PC on which 8.53 or a later version of EDIUS 8 has already been installed, which makes two versions of EDIUS available on the same PC.
Do not deactivate the license when uninstalling EDIUS. Restart your PC as necessary.
2) Double-click the setup file of EDIUS (exe format).
Follow the on-screen instructions for installation.