If you're not covered by the warranty any more you can pay the dealer to fix it or you can take it to any auto glass shop and they should be able to repair it.
My tab fell off last year I went to the my old dealer and for some reason the service guy told me it was not covered and to just go to some auto glass shop down the street. I did get a quote from the auto glass shop I can't remember the amount I think it was under $130... but I ended up going to a different dealership and getting it done under warranty I think that other service guy guy was smoking crack or something...
As for doing it yourself...The guy at the auto glass shop told me they solder it back in place and than they place the glass under some heat lamps for a couple of hours. He also mentioned that these fall off a lot on many vehicles and sometimes you might need to solder them back in place a couple of times. In my opinion it's not worth the trouble have a pro fix it for you.
I soldered mine back on, took 3 minutes tops. Super easy to do if you have a hot enough soldering gun. As a matter of fact, I've had to repair this on every fullsize SUV I have had. My dog's destroy those things with their tails.
Great, another common issue to look forward to. The first Escalade we had (before it was replaced for a transmission issue) had these hanging when we got it and we thought the last owner carelessly broke them. I guess they just come off.
I remember when we had that truck I looked into fixes and found a kit online that requires you to sand down the old attachment point, clean the contact tab, apply a special conductive glue and then put them back in place. They DON'T just glue back on because they won't make a good conductive connection once the stuff rips off.
Call a glass shop. I know ford used to sell the glue, I had to buy it for an old thunderbird I drove. Its a glue/paint with metallic in it, which makes it conductive. I have also used the type to fix the circuits in the older style if they were scratched or cut. Its something that you should be able to do yourself and it beats trying to solder it which can be tricky if you dont know what you are doing!