I just replaced a bulb in mine.
Fairly easy to replace if you know your 4Runner.
I have never seen bulbs like these in my life.
I bought 2 of them, 1 for future use. Each bulb costs approx $4 with tax. Incredible!!
Steps:
Remove lower lid
Unscrew 1 phillips screw that helps mount the control unit
Pop out the control unit but tugging the lower end
Unsnap the white plug for the control unit
Remove 3 phillips screws on the back of the control unit
Seperate the control unit by gently pulling apart (be careful)
You will see several circular pieces (these are bulbs)
Remove the bulbs with a small flat head screw driver and turn 1/4 of a turn to remove. It should come loose and pop right out.
Replace with new bulb