European headlight assembly removal

I need to replace the headlight assembly in my car (base model sedan). This has what Chevrolet called the "European" style composite headlights: the assembly for each side has a single lens that covers the compartments for both the regular and high beams. The bulbs can be replaced by twisting and then pulling straight out of the back of the assembly. Can you tell me how to get the assembly (rather than just the bulb) out? I can see two metal clips near the top on the back side of the assembly that appear to hold it in, but I am not sure if there are additional bolts etc, that need to be removed.