cut+splice, is the way i would do it. solder and shrink wrap the wires, and you should be fine. they come with their own connectors, im sure.
its relatively simple, headlights are one of the easiest electrical circuits evar. 2 wires to each light, doesnt reeeally matter which goes where (unless your wiring for HID's), cut+splice, test and make sure they turn on, and done!