Navigate to Transport>Operational Tasks>Consignments and filter the screen to the consignments you wish to reprice.

Use the select All option as below or select the required consignments individually.

Once selected as below select the Bulk Action Tasks option highlighted below, toggle the Reprice Consignments option to "Yes" and press "Ok"

You will then be presented with the below screen and receive an email once the systemm has completed the reprice.