Lb7 vin change v2

Can anyone help me out with this, I have a lb7 that had a dsp2, I've made quite a few mods, now tunes most likely need updating because it doesn't run as well as it used to, also it's locked and have no idea who tuned it. I purchased another ecm with dsp5 unlocked and a v2. Is there a way to change the vin# without having to use 1 of my licenses. Other update info would help as well.
I guess is there a way just to update the vin#.

The licenses are not locked to the VIN, they are locked to the ECM so unfortunately you cannot use your existing license on a different ECM even though they are in the same vehicle.

If you want to change the VIN in the ECM, use the scantool, go Bidirectional->Change VIN... no flash license needed.

( and as GMPX said, the flash license is locked the the ECM itself regardless of VIN )