Finger Scanner problems on S5

[AC Question]

HELP! I'm going crazy trying to figure out how to remove my fingerprint scan login method because out of about 100 tries, it has only worked 2 times and then I have to type in the backup password anyways, so I might as well get rid of the fingerprint method. I have looked everywhere and can't figure out how to change it back to any other setting - if I click on the finger scan box to open it, there is no choice to delete it or change it. What am I doing wrong? I am not a smartphone expert - I just got the phone last week after having an old BB for years. Thanks to anyone who can help me.