Depending on the model some slide out the side and can be replaced fairly easily. Some others however you need to take the door apart in layers to get to it. Sometimes it can be time consuming. But most are replaceable!
When you take off the oven handle, it’s sort of like a clamp and the glass should slide right out (be careful because it could also fall out). Then just piece back together and refasten. I’ve done it, it’s pretty easy.