How to attach the turn signals to the front?

Would like to mount the front turn signal instead of the light bar. Now the lamp cover offers itself, there the lower screw thus no collision with the tank arises. But the question is how do I get the cable cleanly through? The turn signal itself always have a hollow screw through which the cable is led. But if I put the turn signal into the lower screw connection now, how do I get the cable cleanly to the back? There should be no cellar men as in the picture, but d The new turn signals are to be fixed there. Thank you for your help…