OK so to be complete you need four things in a complete fob:
1) Case. $6 on ebay with uncut key
2) Key: included in case, most locksmiths can cut.
3) Circuit Board. Does remoter lock/unlock/panic requires battery. Can program on car.Range up to about 30 ft.
4) RFID chip. Used by SKREEM to permit car to start. Special program required. Range: an inch or two.

So the only real issue is the RFID chip that is present in the fob and the valet key. To replace the SKREEM, you must program the SKREEM to both the VIN and the RFID keys. if the SKREEM is working, can you just clone the RFID chip ? YWTK.

I have some RFID chips coming in. What tool (preferably PC based) is required to read from one RFID chip and copy to another ?