I have always wanted to install a toggle switch to control the factory DTRL. There are times with stealth is required and having bright orange lights is counter productive. Let's not debate the merits of the DTRL system.
I have reviewed the factory wiring diagram for the 2007 Tacoma which should be the same for the 2009 models as well.
As best I can tell all I need to do is insert a switch between the body ECU and the signal flasher @ wire/pin #12 (Light Green & Red wire). According to my notes the 1M junction block wire harness is driver side lower finish panel.