

The biggest request came from UC San Diego, which said it needed 5,000 new 5.56-millimeter caliber rifle rounds to replace ones used in trainings
Not sure how many officers they have or what the training regimen looks like, but 5,000 does not seem like that much to me. Most folks I know go through 120-240 rounds in one range trip and, by picking up deals, end up with at least 1,000 - 2,000 rounds at home. Most of the best deals on ammo are for boxes of 1,000 or more.

There is no way to ‘downgrade’ a fresh installation. Only an installation that was done as an upgrade from Windows 10 can be downgraded, it has to be done within 10 days of the upgrade and that is possible thanks to the Windows.old folder that gets retained for that period.
In your case, you’re looking at a clean install. Once you’ve got your installation media ready, you can make your life substantially easier by using DISM to extract the drivers and integrate them into the WIM file. I’ve had a few laptops end up with no network drivers, no keyboard / touchpad drivers, and no USB drivers - leaving OOBE inoperable.