How do you change the speedometer drive oil seal on a Ford Transit gearbox?

To change the speedometer drive oil seal on a Ford Transit gearbox, first, ensure the vehicle is securely lifted and supported. Remove the speedometer cable from the gearbox, then use a suitable tool to extract the old oil seal from its housing. Clean the area, apply a bit of oil to the new seal, and carefully press it into place. Reattach the speedometer cable and check for leaks after refilling the gearbox with oil if necessary.