Payment Plugin: Firstdata
Login to your VirtualTerminal account at https://secure.linkpt.net/lpc/servlet/LPCLogin
Click to Support -> Download Center
Click on "Download Now" link.
Enter your TaxID and click "API" button.
Upload .pem file into amember/application/configs/ folder using your FTP client.
Back to aMember CP -> Setup -> FirstData (this page), and fill-in the fields.
Run a test transaction.