Replacing glass in rearview mirror ?

Has anyone replaced the glass (mirror) in the rearview mirrors ? I have an auto-dimming, clown nose mirror w/Homelink (3 button remote programmed garage door opener) and the mirror is broken. I got another mirror (non-homelink). They are the same mirrors but I'm not sure how to get the thing apart to replace the glass?

Any help is greatly appreciated !

thanks,

mr