It’s plug and play. I just did 10 headlights recently. All you have to do is swap out your ZKW headlight brackets with the AL ones that come with the headlights in your case. If you buy used AL on eBay you likely will have to dremel out your ZKW bracket like you did or buy new/used AL bracket. Also, you did not install corner light correctly that’s why there is a gap, there should be no gaps. Practice on the headlights they you took off, it’s easier to plug the corner light when you can see where it goes.