Im not sure but im goin the other way around and i have to cut quite abit for the quadlight to fit , have u tested to see if the square light fits ok might need some extra brackets etc to hold it sturdy
And as for wiring im not sure either but the square lamps have a square socket which is earth and i presume high and low beam so surly all u have to do is seperate the live between the quads low n high and spade connecter em to the square lamp
