I tried exactly what you said, and I managed to open up the library in the arduino IDE. But then I got this error.
C:\Users\Clayton\Documents\Arduino\Fingerprint_Scanner-TTL-master\Fingerprint_Scanner-TTL-master\FPS_GT511C3\Examples\FPS_Blink\FPS_Blink.ino:20:25: fatal error: FPS_GT511C3.h: No such file or directory
#include "FPS_GT511C3.h"
^
compilation terminated.
exit status 1
Error compiling for board Arduino/Genuino Uno.