Truck is stalling when switching tunes

[F-127]

Should be OK to run as long as you don't change tunes from calibration to calibration.

PCM disconnection not needed, battery disconnection not needed. Just be absolutely sure the key is in the off position and preferably that the keys are out of the ignition so there is no chance it could be turned while you are removing or installing the chip. Seeing that you have a Super Duty, as long as you have modded the plastic PCM holder/bracket enough to remove the chip without removing the bracket itself, you can get by without disconnecting the PCM. Just make sure that the chip and switch cable are good and secure so they won't get bumped or pulled out while driving.