I have done it, changed it with Amber LEDs....
Easy but be careful!!!!!
Take a flat head screw driver, wrap a rag around it. The bottom of the mirror pull it out as far as you can and put the screw driver up there until it won't go any further, right along the black plastic backing of the mirror. Then twist it.
You will feel it pop out, then by hand start pulling on it. The top clips tuck up in the housing, so when you get to the top part you will need to pull down.
UNDERNEATH YOU PUT A SLEEPING BAG OR SOME PADDING!!!! Cushion is always good when it comes to mirrors!!!!
You will see the light socket, twist it and pull it out.
Don't put too big of a bulb in there, I think the plastic might melt if it gets too hot.