I stumbled upon this thread while googling the reason my 2nd hand dx3r keeps beeping a few minutes after being on. I will definitely being doing this MOD asap.
Alright, got mine done. Overall easy, but annoying. 35% of the time was spent bending a single battery bar to act as a spring/connector for connecting two batteries. 50% of the time was spent putting the battery tray back into the radio. Other 15% was dis-assembly and soldering.