Gen 2 to Gen 3 Headlight + harness swap

Hey all, new to the forum and I've been driving my 2007 Crewmax v8 for about a year.

I'm ordering parts right now to do a front end conversion from to the 2014+ gen. My main concern right now is that I have no idea how to swap the cables out. I have seen videos of people splicing the wires together (see). I dont know much about electrical and wiring. I could definitely as the video instructs but I am not sure if this is a dependable connection or if its too much draw on the old cables.

How would I go about replacing or adapting the cables properly? I'm pretty much a scrub when it comes to working on cars and this is my first project besides oil changes haha

Appreciate it!