I have unlocked them for guys that the GM dealers had updated their PCMs many times. The calibration part numbers have to be the same as the one it programmed last simply changing the vin won't do it unless both vehicles happen to be running the same cal ID numbers. Re flashing with a Tech2 and TIS only works if the last one it is locked to also had the latest cals.
If you know what you are doing you can change the cal. (Aka "segment") IDs to match.

The right thing to do is buy another HPP.

 

Actually, the right thing to do is buy anything but another HPP ... While they may be better than a stock tune, they can never be as accurate and safe for the car as a custom tune ... I picked up the EFILive tuner and never regretted it. Following the available how-tos, which is easy to do as long as you're somewhat used to using computers, I was able to improve my quartermile ET by half a second ... I doubt anybody using the HPP can actually get them values. Additionally, with that tune I was also confident that the motor was not only running better, but also that the AFR and stuff were set correctly for that motor, so that it is running well and safe. Something a "standard" tuning programmed by an HPP (or other fixed-settings tuner tool) can't achieve ...

Just my 0.03$ (inflation ... )

 

I assumed most people would know I meant the right thing would be to not rip Hypertech off like that.