To be certain, you'll need to consult a repair manual specific to your 1992 Toyota Pickup's V6 engine. A shop manual or a reliable online resource (like a Haynes or Chilton manual) will have diagrams showing the exact location and the type of drain plug used (it's usually a bolt). Looking at photos online for your specific engine can also be helpful.
Important Note: Before attempting to drain coolant, allow the engine to cool completely to avoid burns. Have a suitable drain pan ready to catch the coolant. Remember to properly dispose of the used coolant according to local regulations.