What happens next?

How to update the master database of a uniden homepatrol using homepatrol sentinel
Install and open the homepatrol sentinel software.
Backup your device using sentinel, to ensure no avoided channels and any settings are re-scanned the next time the item is turned on after the update.
Bring your device to nearby and plug it into your computer.
For your computer to see your device, you'll need to turn it on. When you plug it in, it'll turn off, so you'll manually need to turn it on.