SharePoint Library Lifecycle Cleanup

Our SharePoint Online document library has exceeded Microsoft’s storage quota and I need to bring it back under control through proper data-lifecycle management. My chosen approach is to delete redundant files, determining redundancy strictly by file age. Anything older than 7 years should be treated as a candidate for permanent removal, provided we remain compliant with M365 retention requirements. Here is what I need from you: • Analyse the existing tenant and pinpoint every document older than the seven-year threshold, using the most reliable combination of Microsoft Purview Data Lifecycle Management, SharePoint Online PowerShell, or any other native M365 tooling you feel is appropriate. • Design and configure the retention or deletion policies so they run automatically going forward, ensuring no disruption to current collaboration. • Validate the policy in a pilot subset, gather evidence that it removes only the intended items, and then roll it out tenant-wide. • Provide a concise hand-over report that documents the steps, scripts, and settings so the client can audit or adjust the process later. Success is confirmed once the library’s size drops below the Microsoft quota and a repeatable, policy-driven lifecycle is in place.