1. First navigate to a workorder with serials generated.
2. Once on the workorder screen click into Main/Etc+. Select Split Line.
3. Once on the split line screen you will see the list of serials you have generated. Select the ones you want to move to the new line.
4. Type in the amount you want to split off to a new line and click split.
5. The serials will be moved to a new line successfully.