Unless your hands are as large as a gorilla's, you will be able to squeeze through and change the turn signal bulbs without removing the bumper or sliding off the headlights. The dealership had quoted $300 (that's not a typo) to install them; that was enough inspiration for me to be creative and resourceful. Just by looking at it, it seems impossible. But when you actually try, you will succeed in reaching them and getting them off.