ShockSmoove

So I have a pair of aftermarket headlights I'm putting on my car. My installer said the bulb wont fit and that I needed a socket to make it fit? Says lots of headlights come with them. I'm not sure what socket he means, nor would it make the bulb fit in. Could I solve this problem by just buying some LED turn signal bulbs, or perhaps a smaller bulb that will fit in the aftermarket hole?

For reference, the turn signal hole is apparently smaller than the OEM one so it wont fit. Any solutions?

All replies and ideas appreciated.