Remove Purchase Order Item before approval with REST API

Hi, does anyone know how to remove the Purchase Order item with REST API? Because right now I can only update the 0 quantity based on line but i cannot remove the item.

PATCH: https://<accountID>.suitetalk.api.netsuite.com/services/rest/record/v1/purchaseOrder/4784185
Payload
{ "entity": { "id": "118015" }, "location": { "id": "218" }, "item": { "items": [ { "line": 15, "item": { "id": "585" }, "quantity": 0.0, "location": { "id": "218" } } ] }}

By the way, when the PO rejected, it can do a resubmit to get approval again, but if you using REST API to update the approval status, even though the status changed to "PENDING APPROVAL", but this button still show there, user still need to click the resubmit button again in order to continue.