Split PO line - JDE inbound transportation

Hi

Is there a way to split PO line in jde inbound transportation → shipment detail e.g. PO line is for 10 units, supplier can only ship 4 and remaining 6 at later stage. How can I update have a shipment no for 4 and remove 6 from the shipment.

P4915 does not allow me to change the quantity. Ideally I should be able to change the quantity and create a new line on the PO with a different shipment no.

Thanks