How do i import 3rd party VST plug-ins into Logic Express 8???

I downloaded some vst plug-ins for logic express online somewhere and the instructions to install them says to go to library/audio/plug-ins/vst and to just drop them in there. i do that, but then when i drop them in there and then start up Logic, they're no where to be found in the program

is there another way you are suppose to import vst's?