If you wish to change your password or security answer then after you have successfully logged in using your current password please click the symbol in the top right corner to enter the settings pages for Your Account.

Next press the option for Account Settings and you will see the above page where you can change your password (or security answer). You can press the eye icon on the right to check that you are inputting your current and new passwords correctly. 

When your new password has been input twice click Submit and you will get an on-screen confirmation that this has been changed successfully.