Can't get battery for 08 Avalanche out. Connected to a holding tray?

Not that simple. There is a hard to see bracket down at the bottom of the battery. It is usually a 13mm or 15mm bolt holding a piece of plastic that holds the battery in place. Other than that its pretty straight forward. Always remove the black cable first and replace it last.

THEIR IS A DOOR WORKS ON SPRING WHEN YOU SET THE SELECTER FOR COLDIT SHOULD PULL CLOSE WHEN THE SPRING COME OFF IS DOESN'T ALLOW THE DOOR TO CLOSE TO DIRECT THE COLD AIR INTO THE VEHICLE.

if you have any knowledge of automotivce electrical, (and that you need to use a "circuit tester" and not a test light) test for power when someone presses the button. it wouldnt be uncommon for most vehicles for the lock actuator/solenoid/duty actuator to wear out, get weak and fail. this is most probable. given that this is an 08, have you checked withe dealer to see if its still under warranty. if we are only talking a few miles and they wont do anything, look in your owners handbook and get the 1 800 number and get GM's customer service involved. cheers.

Typically - Yes.
Some GM cars (and Mercedes) have the battery concealed and it offers a remote positive terminal for checking and charging.
You should connect to the positive terminal whenever possible. The negative side of the charger can be connected to any metal on the vehicle. Ground is ground - all over.
-Jim

if you can start it with a jump but battery doesn't hold a charge it sounds like you have a bad cell or two in your battery. Take it to your local Autozone and have it checked for free

This is the GM bulletin for your problem: 06-08-44-034C.

You need to have your truck compared to another of the same type. If yours is louder it should be replaced.

It is a real pain. You have to remove the whole front bumper cover. I work for a GM dealer and we hate to change those bulbs. Sorry. Is it not still under warranty? Good Luck.

I've never heard that there was a difference in the frames but who knows...