To be certain, you should:
* Consult your owner's manual: This is the most reliable source for the specific location for your Silverado's engine.
* Look underneath the truck: With the truck on level ground, locate the oil pan (a large, somewhat flat metal part near the bottom of the engine). The drain plug will be a bolt on the bottom.
Caution: Before attempting any oil changes, ensure the engine is completely cool to avoid burns. Have the correct size wrench and drain pan ready. Proper disposal of used motor oil is crucial for environmental reasons.