There are two ways to disable your DRL's.
Method 1: Tundra's with DRL's have two gray electrical connectors located between the battery and the inner fender liner. One of these connectors (D2) is fastened to the fender liner and has two black wires leading to the Daytime Running Lamp Resistor, also fastened to the fender.

http://www.tundrasolutions.com/forums/generalinfo/drlresistor.gif

Disconnect this one and your daylight running lights are inoperative. If you change your mind simply reconnect and you are back to stock.

Link to > Location of DRL Resistor (http://www.tundrasolutions.com/forums/generalinfo/tundrlresistorlocation.gif)

see DRL Disable Mod Pic (http://www.tundrasolutions.com/photopost/showphoto.php?photo=6717&papass=&sort=1&thecat=500) courtesy of Ring Steel

Method 2: Link to > Toyota Technical Service Bulletin EL0011-00 (http://www.tundrasolutions.com/forums/generalinfo/recalls/tsbs/EL011-00.pdf)