You just need the trigger, it's pretty cheap from rock auto, local dealers may even sell it for cheaper. You do not have to wait the 45 minutes to program them. You can enter the swap sensor mode without the prompt.
And just to plaster this everywhere, here's the procedure to enter training mode for a different set of TPMS sensors.
From off...
1. Brake once, then turn the car on without turning on the engine, then off... on... off... on. (5 presses of the start button)
2. Brake once again, then off... on... off... on... off... on... and you'll get a honk. (6 presses of the start button)
3. Grab the trigger and go to the front drivers wheel, point the arrow to the bottom of the valve stem (I found that works best) and press the button. It will honk when that wheel is trained. The proceed to passenger front, passenger rear and drivers rear. It will double honk at the last wheel to indicate training complete.