If you need to correct the SCAC:

1) Go to the Main menu -> Organize Tab
2) Select Picks
3) Fill out the Pick number
4) Click on the "Edit" button

For example, the SCAC code and carrier TBD should have been updated to SCAC LGSD (Carrier Logistic Distribution)

1) Select SCAC LGSD from drop down

2) Click on "Switch SCAC" button, then "Ok"

3) Click on "Resend shipment confirmation" button.

As the result, the SCAC was corrected and the pick was resent.