IBM PAW SSL Certificate

[PrabhjotSinghPhull]

Hi Team
Good day

Problem
i have got the Signed certificate from Certificate Authority but, I need to generate the private key, primary, intermediate, and root certificates from pkcs12, Security cert. rsp cert file share by client.
So i can create a .pem file

Suggestions/Answers you seek
Please provide some steps to generate the certs via open ssl or links to with proper steps, i was unable to find any proper solution on google.

Regards
Prabhjot Singh