Changing the Thermostat

[chevy4x4trucks]

Is there a way to change the thermostat without having to drain the coolant out of the system?  Also, how much coolant does the silverado hold?

[Kania2k1]

No, you will have to drain some of the coolant out of the system.  Since the thermostat is in one of the coolant lines, you should remove a little of the coolant.  Not sure of the capacity, but I would guess about 1.5 gallons?