There is not an official "Force passcode change" option, but you can set the time frame down to 1 day to force a passcode change. Then revert back to your previous settings.
EDIT: A faster way that I found to accomplish this is to find the device in the Avalance Inventory, select the "Unlock" option from the top menu bar, update the device.
If the device is locked, once you swipe to unlock it will not prompt for the passcode and will immediately prompt for a new passcode to be set (granted the device is being forced to have a passcode set)
If the device is unlocked, the process will not begin until its locked then unlocked.