[HeR97]

To install John the Ripper you need to download it from this website:
http://www.openwall.com/john/
I am using ubuntu so this is tutorial for Linux
when you downloaded it you shoul open terminal and type:
cd /downlaods/john-1.7.6 or whereelse you downloaded it and whatelse wersion
after that type
cd src
make
make clean SYSTEM
make clean generic
cd /downlaod/john-1.7.6/run
and than type ./john
it will be working but if it isnt go to terminal type john and you will see the text you need to type to install it and after that just type john
enjoy