1.  Once you're viewing the certificate in question, click the “Renew SSL Key” button.

 

2.  Select "Renew with a reissued certificate".

 

 3.  Paste the plain text signed certificate from the provider and click CONTINUE. (Please see obtaining plain text certificate for more information.) At this point the SSL key will have a status of 'ready'.

 

4.  Now click the “Activate SSL Key” button to activate the certificate.