Apple TV2 cleanup

Hi there,

    I have already jaibroken my Apple TV2 and have been using XBMC and also adding Navi-X onto that. I would like to start from scratch and clean up my Apple TV, delete the current instalation of XBMX and Nito. Once its all cleaned up I was lookingto purchase aTV Flash.  Can anyone explain how best for me to go about doing this. Would really appreciate it some advise on doing this and confirmation that aTV Flash (Black) will work. Thanks in advance for all your help much appreciate it.