Serpentine Belt

From the mid 2000s until the 2013 model, you can pull the headrest on your Chevrolet Silverado 1500 up to the full-up position by pressing the button at the base of the inboard leg of the headrest. You then stick a small-diameter tool -- the leg of a heavy paper clip or a small pin punch -- into the hole on the base of the inboard side of the outboard headrest leg. Pull up with the pin inserted and the headrest comes off. On the 2014 Silverado 1500, press the large and the small buttons on the base to pull off the headrest instead of using a pin punch

starter has 2 bolts on the bottom with some shims. There are a few wires one large and 2 small. They are labeled on the solenoid so can be transferred to the new starter. Remember to remove one battery cable.

the best solution is to fit a multi layer type gasket and change the oil rail also a kit is availiable through xparts it is a long lasting repair the old gasket is not good the main reason these gaskets fail is because the engine holds only a small amount of coolant to decrease warm up times to reduce emissions but when the thermostat opens the engine gets a large gush of icy cold water from the radiator the engine components ie cyl,head and cyl block move in relation to each other

The service engine soon light is an indicator /reminder for you to do some type of maintanence work on your vehicle, depending upon your mileage that you have accumulated on your car dictates the sort of maintanence needed on the car.
Can either be as simple as an oil change or as complicated as a major service/tuneup, oil change, transmission change, wheel alignment, brake inspect, tire rotation etc.
Once the work is performed the technician must turn off the light.
Reference the dealership or reliable repair shop for further information.

With your lower unit off have someone shift the engine into forward while watching the gear shift select shaft's rotation,let gearshift remain in forward,now place your lower unit in forward and reinstall. In the future just put engine in forward when installing a water pump as there won't be a need to move gearshift