where can i download it?? how does it works??

Sorry, i am new in this forum, im using mac, i downloaded and its a ziped file, so i extracted and it appears a folder wich contains an rb file called:clf_simple_loft_loader.rb and another folder which contains; clf_simple_loft_small.png, clf_simple_loft.png, clf_simple_loft.rb.
I tried to move them to the plugins and then open sketchup, but nothing.

how do i install it