You can access the New Standard Updates window by going to File > New Standard Updates. The window is comprised of three sections: "Upload," Group Change," and "Split land and Building Leases."
Additionally, at the bottom of the window, there is an option to "Classify All Leases" as of your implementation date. This is especially useful after making an update to your implementation date, as all leases will typically need to be reclassified after that change is made.