How do you rename the Cross-Project Plan(Pre-defined) Type?

Hi

I am unable to find any option/Workaround to modify/rename the Cross-Project Plan(Pre-defined) Type.

All custom Plan Type( like Sprint Backlog, Release Backlog) details are stored in Process Configuration Source. However, no source is available for Cross-Project Plan(Predefined) for both Scrum and FPM Project Area's.
     

Just to re-iterate, I am looking for renaming Plan Type not the created plans.

Already referred below jazz discussions but none works for Predefined Plan Type.
https://jazz.net/forum/questions/219347/rational-team-concert-v601-predefined-plan-types
https://jazz.net/forum/questions/21558/creating-a-new-plan-type

Any idea which locations to look into or any document to refer.

Regards,
Rohit