ok, from what I saw the toyota rep do: with new transmitter button in hand, make sure all doors are closed while sitting in the drivers seat, move the ignition from off to acc 3 times in quick succession. this is then followed by a press on the button so it can learn the code of the alarm. (alternatively the button could be held during the sequence, I'm none too sure) But really, the toyota rep didn't charge me anything to do it, so it would probably be easier to head back down there, it takes literally 1 minute to do it, and it's not too far from where I am :)