From a software standpoint the Trio platform is based on the same (UCS) platform that the entire line of modern VVX phones use, thus the majority of upgrade options are the same.
As covered in various other VVX articles this process is unchanged in the Trio.
If after inserting the USB drive the phone does not appear to recognize the firmware package and does not automatically prompt for the administrator password then an additional manual step may be required.
Once the 5.4.0 Rev BB release has been applied to the phone then this manual step will no longer be required for future updates as the phone will now recognize the correct firmware file names automatically.
Warning: You must watch what you are doing here / backup appropriately - Terminal will happily delete everything on you. Mac Fusion drives are logical volumes created by combining "spinning platter" and SSD drives in software.
Now you should have a case sensitive journaled HFS formatted partition covering your entire fusion drive.
1046: Type was not found or was not a compile-time constant: Microphone Enhanced Options.
Once confirmed the notification icon of a spinning gear should appear in the upper right corner of the display.
In addition if the USB drive contains an activity LED then it should be flashing to indicate that the phone is currently reading the files from the disk.
Here's how you make them using diskutil in Terminal: See all your volumes: diskutil -list Make note of the volumes you intend to use.
In my case that was /dev/disk0 and /dev/disk1 because I was recreating my primary drive into a fusion drive.
After a few minutes the USB drive activity light should stop flashing which means the files are finished copying to the phone.