What new part do you have?
The taillight has 4 light bulbs, or 2 simple bulbs and one double filament bulb.
So you have 4 power wires and a 3 or 4 ground wires, because all is plastic so no metal grounding available.
I would simply write down the wire colors for each bulb and its' function in a little list.
Then you can undo all those wires and hookup one by one to your new part at the correct bulb or led or what you have.
its like a wiring harness kit, its basically has the short strands of wires to a connector that looks like it connects to another bunch of wires that go down the side of the body..
its for a 2006 Hyundai Santa Fe. the tailight has 3 bulbs and the connectors are already assembled and just have to switch it with the old one
I not have seen it at mine if the total harness has another general connector at the side of the body. But I was only changing lightbulbs.
If that connector is the same form you may assume they are made to fit and you need not do anything else and simply hook it up there.
Maybe you need to undo a bit of inner side lining to find it.