You'll probably have to bring the bike first for them to review and send photos (or the frame) to Cervelos. Call the LBS first and ask for guidance. Luckily I didn't have to go through warranty replaecment, but if you search the forum you can find more info. It shouldn't be a complicated process if your shop know what they are doing.
2009 S2, SRAM Rival, 50/34 Rotor Q-Rings, Mavic Ksyrium SLs 7.2Kg