I looked at this thread on Titan talk, but there were a few glaring omissions. Not to bad mouth anyone as it was super helpful, but there's a few Armada specific things (specifically the bumper).
I'm not sure what year the lower grille became fixed into the bumper, but the biggest snag (not that it's that hard to get past) was that for my Armada, the entire bumper had to come off so that you could put a pair of lower mounts for the cooler.
So, the first step looks something like this.
7 quarter turn clips on the upper grille, and then a bunch of phillips head clips and screws for the bumper itself. The only 2 "hard" ones are 4 phillips head / 10mm screws that you need to be able to move the splash shield out of the way to access:
The next glaring omission from that thread was where to mount the bottom of the cooler. The logical place appears to be the main bumper beam.
I went with a pair of RivNuts / Nutserts, as that seemed like the best / most secure option with a blind install on those (ie: you can't get to the back of the hole to install regular nuts).
After that, I fabbed a pair of brackets using the bars that Long Tru Cool includes in the kit. I have NO idea how you'd get a tool onto the backs of these to tighten nuts or bolts, so I took cheated and broke out the big guns, and welded on a pair of weld-nuts onto them. This way, the brackets can be bolted in place to the bumper bar, the cooler can be lowered in place, and then you just have to worry about tightening the bolts:
A test fit before painting the brackets, so that I could fab up the upper bracket.
Because there's not really any load on the upper bracket and it's mostly for positioning the cooler at this point, I decided to only do a solitary bracket there. Did another riv-nut in the plastic (!?) bar below the horns, and welded another nut to the back of the bracket for the cooler mount. There's a bit of steel in the way, but you can get a t-handle under that cross-bar to tighten up that bolt:
Installed. Note the hose that comes out near the passenger side of the cooler. There wasn't a ton of clearance between the hose and the cooler, so I wrapped it with a piece of 3/8" fuel hose I had sitting around as a buffer between the metal and rubber hose.
And back on the ground to check everything for leaks after filling it with fluid.
Presto! And now I don't have to worry about the radiator oil cooler taking a crap and f**king up my transmission. Win!
I'm glad I hit the brackets with a little black paint. You can't even tell anything not-stock is back there if you didn't know any better.
If you're interested in using rivnuts but are turned off by the cost of the installation tool, you can make your own with a piece of 1/8 or 3/16" flat stock, a Class 10.9 flange-head bolt and a drill. That's what I did to install a few of them on my racecar, and used it again to do this project, and it works great.
I have details on how to make your own HERE, or you can buy one here (no affiliation). But it's basically $10 for a piece of steel bar-stock and a bolt. That's a hell of a mark up...
For something like this, there's no reason to go any bigger than M6, so that's what I used. If you don't happen to have a box full of M6 hardware, here are a few helpful links:
Zinc-Plated Steel Cap Screw, M6x1mm, 16 mm long
Zinc-Plated Steel Rivet Nut, Open End, M6x1.0 Thread
NAPA Fuel Injection Hose Clamps for 5/8" OD / 3/8" ID hose.
Hopefully this'll help someone else.
I'm not sure what year the lower grille became fixed into the bumper, but the biggest snag (not that it's that hard to get past) was that for my Armada, the entire bumper had to come off so that you could put a pair of lower mounts for the cooler.
So, the first step looks something like this.

7 quarter turn clips on the upper grille, and then a bunch of phillips head clips and screws for the bumper itself. The only 2 "hard" ones are 4 phillips head / 10mm screws that you need to be able to move the splash shield out of the way to access:

The next glaring omission from that thread was where to mount the bottom of the cooler. The logical place appears to be the main bumper beam.
I went with a pair of RivNuts / Nutserts, as that seemed like the best / most secure option with a blind install on those (ie: you can't get to the back of the hole to install regular nuts).

After that, I fabbed a pair of brackets using the bars that Long Tru Cool includes in the kit. I have NO idea how you'd get a tool onto the backs of these to tighten nuts or bolts, so I took cheated and broke out the big guns, and welded on a pair of weld-nuts onto them. This way, the brackets can be bolted in place to the bumper bar, the cooler can be lowered in place, and then you just have to worry about tightening the bolts:

A test fit before painting the brackets, so that I could fab up the upper bracket.

Because there's not really any load on the upper bracket and it's mostly for positioning the cooler at this point, I decided to only do a solitary bracket there. Did another riv-nut in the plastic (!?) bar below the horns, and welded another nut to the back of the bracket for the cooler mount. There's a bit of steel in the way, but you can get a t-handle under that cross-bar to tighten up that bolt:

Installed. Note the hose that comes out near the passenger side of the cooler. There wasn't a ton of clearance between the hose and the cooler, so I wrapped it with a piece of 3/8" fuel hose I had sitting around as a buffer between the metal and rubber hose.

And back on the ground to check everything for leaks after filling it with fluid.

Presto! And now I don't have to worry about the radiator oil cooler taking a crap and f**king up my transmission. Win!
I'm glad I hit the brackets with a little black paint. You can't even tell anything not-stock is back there if you didn't know any better.

If you're interested in using rivnuts but are turned off by the cost of the installation tool, you can make your own with a piece of 1/8 or 3/16" flat stock, a Class 10.9 flange-head bolt and a drill. That's what I did to install a few of them on my racecar, and used it again to do this project, and it works great.
I have details on how to make your own HERE, or you can buy one here (no affiliation). But it's basically $10 for a piece of steel bar-stock and a bolt. That's a hell of a mark up...
For something like this, there's no reason to go any bigger than M6, so that's what I used. If you don't happen to have a box full of M6 hardware, here are a few helpful links:
Zinc-Plated Steel Cap Screw, M6x1mm, 16 mm long
Zinc-Plated Steel Rivet Nut, Open End, M6x1.0 Thread
NAPA Fuel Injection Hose Clamps for 5/8" OD / 3/8" ID hose.
Hopefully this'll help someone else.