If you go on youtube, there are some vids that show you how. I have done it on our oven and it was pretty easy but works better with two people. For my oven you take the door off and lay it flat and there are four screws that hold the front piece on and then it lifts off and you can get tothe glass.
When I am doing something like this I grab the digital camera and take pics at each step so when I am putting it back together if I cant remember what went where I can just look at the pics.