Took the NAS down during low usage hours, to swap out the USB drive FreeNAS is installed and running on.
Copied the config from the old USB and pulled out that drive
Threw in the new 32GB Sandisk USB 3.0 drive and my trusty OS Drive and installed the latest version of FreeNAS
Initial setup went off without a hitch
Booted off of the new USB and logged in, then uploaded the old config
Rebooted and everything was back
Whole process took less than 30 minutes.
FreeNAS is the shit.