Is there a how to tread on how to install an HID kit for the 7th gen celica's?

I ordered a kit and while installing them, I noticed that the new HID bulb doesn't have that backing on the back of the original bulbs, therefore when the spring tensioner is locked, the bulb still has LOTS of play. Customer support for the product said that the backing is interchangeble but I don't see how? I will post pics once this weather gets any better.

Anyone else with generation celica have the same problem?