Wire one side of the switch to +12VDC
Wire the other side of the switch to the relay coil
Wire the remaining relay coil to ground

When you flip the switch, the relay points will close.
check the unwired relay points for continuity
switch on = 0.0 Ohms
switch off = infinity -

Wire one side of the relay switched points to +12VDC
This will be a heavy wire maybe #10-12 with an appropriate fuse to the battery,
and put the fuse close to the battery.
Hella will tell you how many amps for the lights, you can use an in-line fuse holder.
The remaining switched points wire from the relay to the lights- (same heavy wire.)
The remaining lights wire to ground. (same heavy wire)
Use the common ground near your battery,
You can find the ground points in the wiring diagram for your car.
Use a factory ground point. Not everything is suitable.
Make sure to secure all wires with tie wraps

Good luck, Bill