To change the source library you will need to use a product like Sequel as Abstract does not have this mechanism.
DSPOBJD on all programs in the library. Choose *SERVICE for the Detail, and send the results to a file.
Create a view over that file that finds the records for the source library in question. This view will then produce a list of the programs you want to change.
Use RUNCMD and CHGSVCDTA commands to specify the change you want to make, and then the View portion of that command would create the list of program names that could be substituted into the correct parms in the CHGSVCDTA process.