Hi,
Please check doc: http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/402891a3-7f89-2c10-3097-91556442b8b5?quicklink=index&… which explains the step by step procedure for sending the project stock for subcontracting.
If you want to scrap the project stock, you may use 551 Q movement.
Regards,
AKPT