One of the heated seat controls has a burned out bulb. Has anyone had to change these? How'd you go about it?

Its probably a LED, you might need to replace the circuit board.

if it burned out it's probably a lamp... LED's very rarely go out in my experience...... i still doubt any parts would be available frtom Lexus, you probably just replace the switch.... but any local electronics shop or radio shack-ish place should stock both lamps and LED's....

I have a feeling you might need to change the switch. Sometimes the dealers dont sell just the bulb. I know when the rear defogger on the Odyssey burned out a few years back they sold me a whole new switch all because they didn't sell just the bulb behind it.

just replace the l.e.d.,it is available at any electronics store, easy to replace as well. just pop out the switch pop off the cover of the switch and remove the little green rubber hoodie on the l.e.d., then pull the wires out of their little grooves and voila. reverse the order with new bulb.