Hi, I have an 07 CTS with the standard headlights and I was looking to upgrade to HID's. Originally I was just going to buy an HID conversion kit but I was a little unsure of that because my car is a lease. Instead, I came across a good deal for a complete set of stock HID headlights. Now, how easy would the swap be, or is it even possible to just take out the standard headlights I have and swap in the factory HID headlights? Thanks in advance!