These are the steps you need to follow to create a CSR for Plesk:
Log onto your Plesk 7 Control Panel.
On the left, locate Domains. Select it.
Select the particular domain you want to generate a CSR for.
Click on Certificates.
Click on Add New Certificate.
Enter the required information on the page.
You will return to the Certificates menu. At the bottom of the page there will be a list. In it, select the certificate name that you just generated using the instructions above. You will find a text box on the page called CSR. Copy the contents of this text box into a plain text editor program.
The contents of this box should look something like the following: