I just did this myself a couple of weeks ago. You have to take off the front grill and bumper. I signed up with alldatadiy.com to get the diagrams for disassembling your entire truck

I think it was $15 CAD to get access to the documents for a year.
Only problem was it showed diagrams on how to take off the front bumper but what it didn't tell you is that you need to take off the front wheels and wheel well covers as well so you can access a couple of the bolts for the bumper.
Took me and a buddy about 2 hours to do the whole job. My buddy is very experienced at this type of thing so it probably saved some time.
My advice: Make sure you aim them properly before you do the final tightening of the bolts to the frame. It's almost next to impossible to adjust the low beam lights after everything is back together. The high beam lights aren't too bad.
I'm really happy with them and they look really cool. I'm looking to upgrade the H1 bulbs in them though.
One thing I did notice was the molex connectors were a bit flaky and don't connect that well so the lights would flicker when you moved the wires around a bit. I just "adjusted" the pins in the male end to give them better contact with the female end and that seemed to fix the problem.
Hope this info helps!