google it and you will find some links or just go to cheatengine forum and search it there
search on google cheatengine cheat engine cheat engine downloads cheatengine forums
and you will probably find it
http://cheatengine.org/downloads.php
yes if you want to its free aswell
You can download it at: http://cheatengine.org/
press the download button
To install cheat engine you can go to the related link, then you're just one click away from installing. Please note that although the cheat engine program itself is not illegal, using it for illegal...