Replacing Driver's Side Mirror w/o buying new heating plate

There are three screws under the side mirror assembly. Have you tried removing them first? I think you better off replacing complete assembly due to space to work with and plastic components.

 

I'm pretty sure this is the part you're looking for (assuming you meant the left side, you didn't exactly say but I guessed you parked with the left side out).

As you can see by blowing up the pictures, it's a sandwich of the mirror glass and the heat element, mounted (with really good soft adhesive) into a plastic frame. The whole thing just snaps in and out of the mirror assembly; you can change it in seconds once you know how to pop it out and in. (A saving grace for that is the old one's already cracked, so you won't feel as shy while you figure out the trick.)

I wouldn't recommend trying to separate the goop sandwich and glue in separate heat layers and bare glass. Life's too short. (I did separate one years ago just to see if I could, and I still have tools from that experiment that I have never fully removed that really good soft adhesive from.)

-Chap

Edit: I found the old post where I described how they unsnap and hinge out. That was a Gen 1, but you can see from the parts link photos above that the construction hasn't changed. The two clips that unsnap are at the bottom, and a little round divot in the plastic edge lets you locate where one of them is. The tabs at the top act more like hinges, and will slide out after you unsnap the bottom and tilt.