Linux and Mac users: update your @envvar{PATH} to include @filepath{/path-to-new-racket-directory/bin/}. Then you'll have access to @exec{raco} (see @other-doc['(lib "scribblings/raco/raco.scrbl")]).
Mac users who haven't done this before: @link["http://architectryan.com/2012/10/02/add-to-the-path-on-mac-os-x-mountain-lion/"]{these instructions} are simple and accurate.
Windows users, I'll trust you to convert @exec{raco} into the appropriate command for your system — assuming defaults, it's likely to be @filepath{C:\Program Files\Racket\raco} (include the surrounding quotes in the command).