Use this call to remove a tag from a shipment. You'll need both the shipment_id and tag_name to perform this action successfully.
DELETE /v1/shipments/:shipment_id/tags/:tag_name
DELETE /v1/shipments/se-2102034/tags/east_warehouse HTTP/1.1
Host: api.shipengine.com
API-Key: __YOUR_API_KEY_HERE__If successfuly, you will receive HTTP 204, No Content in the response.