I had aprox. 30,000 since dealer did last flush, and I decided to tackle it this time myself.
If you want to do it yourself, here's how.
Gather the following tools and materials: catch pan, pref. rectangular shaped, brake parts cleaner, rags, oil absorbent, 4-6 qts ATF+4 or power steering fluid, vice-grips or pliers to open hose clamp, a long funnel or an empty qt. bottle will do, a syringe to suck excess fluid if to full, and a helper. Can do it by yourself, but constantly starting/stopping engine.
The oil cooler is underneath, on the drivers side. The hose that doesn't have the mesh screen is the one you want to remove. Shove catch pan underneath and remove hose. To flush the cooler, just dump fluid into the reservoir until it comes out clean. To do the rest of the system, point hose toward catch pan, and have helper dump fluid into reservoir until clean fluid is running out of hose, have to dump fast. Shut truck down and hook hose back up. Check level and restart truck. Move steering wheel back and forth to help remove air if any, shut off and recheck level. Add, remove until full cold mark is reached. You might want to use a little brake parts cleaner to remove any fluid spilled in engine compartment.
Keep in mind the vehicle I serviced was my 06 Dodge 2500. Your vehicle may differ.