Changing the mileage in GM vehicles is vital when recycling a used BCM module. Using the GM DPS software and this particular DPS type4 application file, you can achieve this.
To display the Type4 tab option on DPS, you need to install GM Techline connect and run the SPS programming option or copy these two files, dllsecurity.dll and tisvcsv4.dll, to C:\Users\Your_UserName\sps\nativelibs, folder.
Watch this video for the process.
DPS Type4 mileage change file