2000 Chevy over heating

Guyz,
Last night on my way home from work, i saw my temp guage proceeed to go higher than normall. I pulled over and did not see a leak or smell anything. So i tried opening the coolant tank and then everything started pouring out the exit hose. So i went to autozone and bought a thermostat and some dex coolant.
I tried to replace the thermostat with the instructions from autozone, but was not able to remove it. The exhaust pipe that goest from the front of the car to the back was in the way and could not take it out.

I did read a few write ups on over heating,

my question is
how do you bleed the cooling system on these cars, and how do you change the thermostat.

Please any help would be great

thanks

Remove the throttle body from the upper intake, don't remove the throttle cables and lay it to the side. remove upper rad hose from t-stat housing, detatch heater coolant pipe from above the water pump and shift aside, remove thermostat housing bolts, remove thermostat.

Or turn the car on let it run for five minutes with the heater on full turn the car off after the five minutes then open the hood and go to where the water pump is located on top you should see a water line the has a small screw but wait open little by little if you do you should see some bubbles which means that the system has air in it contunie to open it when you just see antifreeze come out you have bleed the system. Well, the change the termostat well, you have to remove the all that is front of it cause just like that you won't by the way just to be safe on good side also change the temp sensor.