Give the process some quality time. It is NOT difficult, but, small hands do help. You go from UNDERNEATH the vehicle up through the hole above the trans housing with the cable. That is the size appropriate direction. Start from behind the transmission to thread the cable towards the front of the car - LEFT side of the trans. Then seeing where your previous cable was fished behind things under the dash is helpful. You'll be going above and below a lot to make sure you have the slack you need ahead of the rubber gasket that seals that hole. I noticed on your transfer case image, with the cable coming from the transfer case, that your cable was kinked (that's where it broke), and was routed almost straight above the tcase - which is not how mine was, there is a bracket to the left of the transmission that the cable attaches to, then it goes ABOVE the transmission (along it, there is another holding spot for it just to the left side, above, the transmission. And by LEFT, if you are sitting in the drivers seat, it is to the LEFT side of the vehicle I'm referring.
It tucks nicely up there, NO kinks, and has a spot to strap it to. For the rubber gasket, its not that hard...yes, it SUCKS to fiddle, and you'll be fiddling for a few minutes, but use some slick silicone grease (light spray coating) or rubber care and once you get one side of the gasket to bite, you just keep working it to get it all in. It IS helpful. Think about critters coming into the cab and building nests..yes a mouse fits nicely through that hole - or water coming in on a rainy day.
Make sure you have no super tight turns like you previously had, that will cause issues with the cable.
I literally did this project last weekend, and it takes longer than expected since it is the first time you're attempting it...after this time, you'll be a pro...wait another 140k...and you get to do it again : ) No extra strings, tape, anything, it simply is stiff enough to go where you need it.