I took my radio apart somewhat and I was unable to find the bulbs.
I bought a used unit off eBay because I wanted to keep my 4Runner original. It lit up. Two months later the CD stopped working.
I finally put a new Kenwood single DIN in a couple of months ago. It required that I take out the factory amp. I got it from Crutchfield. It took about 20 minutes to install and it sounds great. I didn't change the speakers and they sound much better with the new unit. Plus I can easily play my iPhone tunes.
Here's a good Youtube on how to get in the dash:
How To Install A Head Unit And Speakers Step By Step - YouTube