Hi Jaun,
I understood that currently you are using EHP6 WDA applications exposed via SAP Portal 7.0 now you are in the process of upgrade portal to 7.3 and what is the new content or changes needs to be done to work with portal 7.3. If I misunderstood your requirement, Please revert back
Since you are already on EHP6 I am assuming you are using all ESS applications based at WDA. In that case once you upgrade your portal to 7.3, deploy the EHP6 compatible (based on PAM) ESS portal business package , so that you will get new portal content which will work with EHP6 ESS WDA applications.
Thanks
Krishna