Once you have renewed a license or completed an IPDP cycle, you will want to mark the IPDP complete and then archive the files you have uploaded to Frontline. PD can only be used once per license cycle. Once you have a new IPDP, you will want to archive the documents you used during the previous cycle to keep your list of files current.
Once your IPDP has expired, you need to mark it complete. Then you can start a new one!
When you mark an IPDP complete, Frontline should prompt you to remove uploaded certificates for that IPDP cycle. Since you are marking it complete, you can archive the files!