How to disassemble the dash on a Previa

[John Kaufmann]

If you are only going to replace the dummy lights in the main cluster you don't have to remove or unplug the cigarette lighter, drink tray or radio. You just need to get the radio fascia off, giving access to the 2 screws on the instrument panel hood.

If I understand what you mean by "dummy lights", those two light bulbs in the HVAC panel can be replaced fairly easily, as you say. (As Jonny says, as long as you leave out those two 8mm-head screws that retain the radio from below, you don't need to do anything below.) As you say, you can just remove the radio fascia and replace the bulbs (though it can be awkward to pull them out without breakage).

However, those lights are part of the blower switch harness (wiring assembly), and are replaced with the switch, which is how I did it the last time. AFAICS the HVAC panel must be removed to replace that switch.