Is it easier to remove the engine on a 2012 Range Rover from the top or the bottom?

A fuel issue. I'm trying to cover all bases . Where is the airbag ecu located at? I want to make sure the inertia switch isn't activated.

I would like to know where the Fuel Pump relay and the Inertia switch is located at on a 2012 Range Rover HSE with a 5.0 liter motor.