heated mirror

I tried the search engine on this topic, but with no luck. I have an '02 Yukon with the passenger mirror not heating. The mirror movement is still working. 1) Is there a continuity check I can do from the connector to see if the heating element is open? 2) Is the heating element external to the glass where i can solder an open or replace it separately? 3) How does the mirror get removed...pry it? 4) What do replacements cost if I mess this one up?

Thanks in advance!