Many Bothans died to bring us these EcoDiesel-specific photos.
The blue arrows in the following images point to the locking collar that must be rotated counterclockwise (facing the back of the bulb) in order to release the bulb:
A followup photo once the D3S bulb has been removed. This image is rotated by a few degrees due to technical limitations of the composition. The eccentric aspect of the bulb housing hole is actually vertical. Blur in the foreground is the bulb wiring harness.
Facing from the front of the vehicle looking into the engine compartment, this is the passenger side bulb once "more room" has been made by unmounting the coolant reservoir and the ECU. For reference, the square metal housing of the D3S bulb is about 44 mm (aka 1.75 inches) per side:
Taken from inside the engine compartment, driver side, with airbox removed. The vertical rubber cone on the left is part of the airbox mounting hardware. Observe how much more space is available compared to the passenger side, as well as the limited amount of slack for the bulb's wiring harness. Also notable is the broken ceramic insulator on the bulb's electrode. Ouch.