You need a ftp program, and mIRC, once your in mIRc join the server efnet, then join the room #xbins, once in xbins type in /msg xbins !list, from there you will get a message with login info, put that info into your ftp program and start downloading. You could also download the emulator from torrent sites such as
www.bt.xbox-sky.com.
here is the full guide to xbins:
http://www.xbox-scene.com/articles/xbins.php