behind the spedometer, one of the bulbs has burned out. Where do I find replacements and is it hard to replace it myself?

I can't answer your questions, but I will say I have the same problem along with another Explorer owner that I know. You are not alone. It's likely to be as common as eroded radius arm bushings.

Go to the project page on this site about installing the white face gauges. You should be able to follow the same steps as that project to get behind the gauge cluster. The bulb should be listed in your owner's manual. It should be a common bulb.

http://www.explorer4x4.com/white_speedo.html

Okay, I replaced the bulb, but it was a pain! I put the dash back in, hit the power button on my stereo, and no power goes to the stereo. Anyone know what I did to my stereo by messing with the dash to make it not work? Thanks

Did you have to unplug the stereo when you did it?
Maybe you forgot or didn't get it plugged in tight enough. Just a thought.

Well, went to my dealership and got the radio removal tool, unplugged the radio, and sure enough the harness was disconnected. How that happened, I'll never know. Thanks for all the help.