Answer
A tenant admin uses the Microsoft 365 export tools, or an eDiscovery export for mail and Teams. SharePoint Migration Tool moves libraries out in bulk.
What it holds
Team sites, document libraries and lists.
Find the size
The SharePoint admin centre lists storage per site collection, and Microsoft 365 admin centre reports the tenant total.
What to enter on the form
SharePoint in GB, and the year your company started using it. Seller form