How do you access the fire extinguisher in the FWD LAV on the ERJ?

To access the fire extinguisher in the Forward Lavatory (FWD LAV) on the ERJ, using the O2 tool to open the compartment door is the correct method. The O2 tool is specifically designed to assist crew members in accessing various secured compartments on the aircraft, including emergency equipment storage.

In this context, the O2 tool serves a critical function, as it is generally included in the emergency equipment kit and provides a safe and efficient means to access emergency supplies without causing damage to the aircraft’s interior or systems.

The other methods, while they might seem plausible, do not align with the established protocols for accessing safety equipment onboard. For instance, prying open the compartment door could lead to damage and is not recommended, while searching for a hidden latch is not a standardized procedure and might waste precious time in an emergency. Unlocking with the pilot's key is also not applicable in this situation, as access to emergency equipment like a fire extinguisher is intended to be quick and readily available for cabin crew without necessitating pilot authorization.