Create the CSR using the instructions at:
https://www.networking4all.com/en/support/ssl+certificates/generating+a+certificate+signing+
request+%28csr%29/microsoft/microsoft+iis+5.x+-+6.x/
And then install the certificate using the instructions at:
https://www.networking4all.com/en/support/ssl+certificates/installing+your+certificate/microsoft/microsoft+iis+5.x+-+6.x/