Hello,

To transfer a product you should create a picking order, add your stock move to it and call validate function of stock picking.

You have added a sale.order tag in this question, if you are trying to change status of delivery of sale order:

-call validate function(do_new_transfer) in stock.picking to update values and change status to done

-when you call the validate function you should pass all argumentss correctly

This link may help you to call methods from xml-rpc