Open the IIS applet, click on the server, choose 'Server Certificates
Click 'Create Certificate Request' in the Actions area
Fill this in as shown
Name the cert
Navigate to your cert provider and enter the CSR you just created. There will be a few steps here to verify who you are, it varies by vendor.
They will email you the cert. Store it on the server.
Choose 'Complete Certificate Request' in the Action area
Fill in this form as show, and you're done.
