February 1st is the deferral deadline.  You can transfer to another runner all the way up until the race expo.

Step #1: Sign into your www.runsignup.com account.  Be sure you use your same email and password that you signed up with.
Step #2: Click on your PROFILE
Step #3: Click on MANAGE REGISTRATION
Step #4 Click the 3 little bars at the top left corner to see your options for transfers, deferrals and checking your registration.