This is WHAT, not how, you can do at the time beeng.
1. Download the beta client
2. Get in to the main menu, bypassing the login screen.
3. Watch replays. In game replays not only a list of replays in the client.
4. Open a command prompt.
That is all, not saying that it is little.
For info on HOW to do that stuff mentioned above you can go to the main wiki @ http://botdev.org/doku.php?id=tutorials (http://inquistor.info/darkblizz/wiki/doku.php?id=tutorials)