Texas, first off, give Muth a call/e-mail and see what they say about the mirrors. They may send you new mirrors for free (glass only). This was a known problem and there was a time where they were sending out free mirrors to those that wrote them. I am just not sure if they are still doing that or not.
As for replacing the glass, it isn't something that is really hard. But, you do need some hand strength as you need to pop 2 friction clips inside the housing and you will also end up pulling the gears over the motor assemblies. When you are pulling the mirror out, it is going to sound like you are destroying the mirrors. Honest. It is just fine. It is going to sound like you are stripping out the gears. Keep pulling. Adventually they will pop out. When you get the new glass, you will see where the 2 friction clip (ball joints) are and then you have 2 more posts where the gear stems snap into the mirror.