I am unable to remove the driver side third row seat. Any clue as to what to do? The #1 trigger will not release and the #2 trigger appears to be released but the hooks are still holding the seat down.

 

Welcome to the forum..

Try seating it firmly down and fully opening it and they try removing it again as something may not have latched or unlatch correctly the first time.
If its still stuck I check for something caught up in the latch like carpeting or other loose items...

 

Is the seat in the folded and upright position? I finally had to take my daughter's Denali to the dealer to get one of the seats out. Took him about 20 min. to remove. Real PITA.

 

I'll try sitting in it to make sure it's not something simple, if that don't work I'll let the dealership have a go at it.