NB: Make a backup of your existing website before beginning installation.Download the module here
Save the file to your hard drive, and unzip it.
Copy the contents to the folder modules
in your Drupal Commerce installation. No existing Drupal Commerce files are overwritten.
Log in to your Drupal Commerce administration, and go to Site Settings -> Advanced Settings -> Modules
as shown in image 1.
Find and check both ePay modules in COMMERCE (EPAY)
, and click on the button ‘Save configuration’ at the bottom.
The payment module is now installed and must be activated.