Does it show up at all in USB mode as any sort of device (either serial OR as an incorrect CW-Lite)? If either of those show up can likely fix it externally.
If no USB activity at all, might need to do the manual recovery.
For opening the enclosure - basically you remove the 4 screws on each end. The end plates then should pop off.
The front panel (with LCD) and inner board all slide together as one unit, as there is a small flat-flex cable connecting them. Let me know if doesn’t make sense as can make a short video.
Will make a note to change the default to try and validate the FW Image or at least confirm with user! As understand how easily this could happen.