So here is what my oven glass looked like when we moved in.
And here is what it looks like now
Want to clean your oven? I promise its super easy.
Add about a 1/4 cup of baking soda in a dish and mix just enough water to make a slightly runny paste.
Spread your mixture all over your glass (and the door if it needs it too. Mine did).
Wait 15-20 minutes (or if it is really, really bad like mine you can wait 30 minutes. Not sure if this is necessary but that's what I did.).
After 15, 20, or 30 minutes wipe off. If there are still spots left they should easily scrub off with a scour pad.