Simply delete the XUnleashed directory, but if you wanted to you could just move that directory to wherever you wanted to install it to.
As far as the harvest bot, go grab the latest Harvest Bot 1.45 version from the downloads section, and extract it to the /Scripts folder in your XUnleashed directory. Then edit the .ini file with your settings.
In order to extract the rar file you will need a program like WinRAR which can be downloaded on a trial basis from
www.download.com