The heating element is a rather cumbersome piece behind the mirror and it's got silicone all around it on the backside.

The mirror just pops on to the adjuster assembly.
It's kind of nerve racking to remove one, but you just
reach behind it and pop it off... it's held on in several places, but once one is free, the others come easily.

Try sending Jerry Lemond a note at jlemond@bellsouth.net

I think he has the replacement glass with the heaters.
If not, he can get them for you (factory parts, not aftermarket) and will do so much cheaper than you'll get them at the dealer.

He can also give you some tips and advice on removing
the old ones and installing the new ones.