The way I've always done it is to edit the /usr/local/psa/admin/conf/httpsd.pem file and put in your certificate information. Note you have to have a valid certificate in order to do this. For instance, your file would look like this once you are done:
-----BEGIN RSA PRIVATE KEY-----
your private key goes here
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
your certificate goes here
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
if you have or need it, the ca certificate goes here
-----END CERTIFICATE-----
Then run 'service psa stop', then 'service psa start'
Then access by the domain name you have the certificate for instead of by IP. For instance, if the cert you installed was for
www.domain.com, use:
https://www.domain.com:8443