The first step is to visit the RPG website,  On the left of the webpage is a box titled Logins.  Under that is a link titled "FSA Login".  Clicking on that box will open another window where you will need to enter your participant ID and password.  If you have never signed into your account before, the default settings will be your Social Security Number as your ID and the last four digits of your Social Security Number as your password.  After logging in using those settings you will be prompted to reset your ID and password with values of your choosing.