It only takes one! EZ! Get a stepstool, and unplug the unit (mine was plugged into an electrical outlet in the cupboard above the unit.) Then, just unscrew the two little screws on the front - in the vent panel above the microwave door and lift off the panel (this is a good time to clean it - I was suprized how yuk! greasy it was, even though I wipe it off all the time!) Then, inside behind where the panel was, in the middle, there is a single screw holding the light unit - unscrew that, and lift off the top and reach down in there - to the right you'll feel (or see, if your stepstool is taller than mine!) the lightbulb, hallelujah! Check this out - my bulb wasn't burnt out, only loose! So I tightened it down, plugged it back in and - happily, "I saw the light!" Found this out by reading the manual - we just bought this house, and didn't get the manual, but I found it @ GEAppliances.com. So it was jsut a matter of three little screws - only took about 10 minutes, including cleaning the vent panel before I put it back on.
mrsbrojoe, December 2007