Hi Eric,
Thanks for your reply and good to hear back from you.
Steps undertaken
1> Export-> Model & Data-> Admin Links & Macros & ( Applications under data store) , but Applications under data store are failing and hence Export utility is failing.

Current Actions
1> Export only Admin Links & Macros, Will that be fine.
2> Also while changing cognos config, Should I delete the current content store and recreate a new one... As Current one after has previos data store information, hence its not asking me to recreate PAD..
Can you please brief me on steps here, as am dependent on cognos admin team. Will have to guide them on this.
3> Is there a way to fix failing export applications. :

Unfortunately, had to rollback and now planning to implement changes in DEV in few days before implementing the changes in PROD.
Awaiting for your response.
Please do let me know if any other steps needs to be undertaken.
CogPlan