Anyone had any luck replacing the taillight module on one of these?

 

Yes, I believe I have. It's been a year or two, but as I recall it was straight-forward. I believe I simply removed the tail light assembly from the vehicle, removed the back cover off the light assembly, and then could get right to the guts. The upper bank of LED's were out on the vehicle... I bought a fully functional tail light on eBay "pretty cheap" because it had a busted lens, and swapped just the module... as I recall... and stuck it all back together, and it's been fine since.