Lego 9v Switch Track Help

Please Help! I have a 9v train layout similar to this. I have two trains, one train parked in the green box and one train in the purple box. I am trying to run one train at a time by using the switch tracks to only allow the electrical current to go through the aligned track. Any ideas on how to do this? I have tried to take apart a switch, but couldn't quite figure it out. submitted by /u/SirllustriousTurnip [link] [comments]