Lindsay,
In the DRV2603EVM-CT User's Guide, there is a short firmware programming section. It lists the part number from Digi-Key and Mouser. See snippet below.
Digi-Key: http://www.digikey.com/product-detail/en/850-10-050-20-001000/ED8650-ND/279663
Mouser: http://www.mouser.com/ProductDetail/Mill-Max/850-10-050-20-001000/?qs=HJ60cwpDT2zPYn1F9YEldQ==
Solder this header to the J4 header holes on the MSP430 Launchpad. Then connect it to the SBW socket on the DRV2603EVM-CT.
Let me know if you have any questions.
Thanks,
Brian