Pull/loosen the plastic surround and then remove the bulb. For most of the switches, the bulb socket twists out of the switch and IIRC the ECT switch is that way. It will look obvious to you once you see the back of the switch. Be careful with the long plastic surround/bezel as it will crack easy.
Once you pull it out, you'll see a round piece about 3/8 inch in dia that's got a phillips cross in it. A quarter turn CC and the bulb will fall out in your hand. I have replaced many of various switches over the years and find these the simplest to change I've ever seen. Cdan will get you the right bulb - one's on the way right now for the 97's antenna switch. Some of you may not even realize every single switch is illuminated if you got it used....
just pulling the little grey plug out of the bottom of the switch is alot easyer than trying to disassemble the switch like I was trying to do.
Thanks Doug and Moj
Steven