Please try the below steps:
1. Open the package.ini and look for the .dat file section under General Purpose Parameters. This section starts with [filename.dat]
2. Copy the below two lines from this section and paste them under the new file section that you want as the data container
ReadOnlyData=Package.ro.tvr
MetaDataContainerOnly=1
3. Delete the .dat file section
4. Search for the line Source=filename.dat, you will see that in many places under every file. Replace the value with the name of the new file everywhere
5. Rebuild the package by running build.bat
If there are any difficulties, please upload the package.ini and i can do this for you.