well first they need to allow access to the net. (outside the school global net) (inside the school then school net) then once the net is set you say burst link! and you will be in the blue world where everything is "frozen" to pick your opponent on the list. since me and zarkun are fighting you will only see your names as available opponents while you could spectate our fight. 
in a nut shell; access the net, burst link, pick opponent, fight