1. You need Console (you can get it with "VAC Chaos" - Google it for download)
2. Enter the game
3. Press F2
4. Alt + Tab to get out of the game
5. Type this command in console party_connecttimeout 1
6. Enter the Lobby
7. Wait map to load and then type set g_gametype gtnw and fast_restart
and yes, u can get banned for this