To reorder labels in a group, go to
Ribbon: DM Electrical->One-Line Diagram-> 
Reorder Labels in Group
Pulldown Menu: DM Electrical->One-Line Diagram->Reorder Labels in Group
You will be prompted to select the group of labels you want you reorder.
Select label group to reorder:
Reorder Labels in Group Dialog Box
Select a label from the list. Press the Move Up and Move Down buttons to move the selected label.
Press the OK button to save your changes and update the label group.