To be certain, you should:
1. Consult your owner's manual: This is the best source for the precise location.
2. Look carefully at the bottom of the radiator: It's usually a small, threaded plug, often made of metal. It may be slightly recessed.
3. Use a flashlight: This will help you see better, especially if it's a bit dusty or dirty.
Important Note: Before attempting to drain your radiator, ensure your engine is completely cool to avoid burns.