Well I can tell you just go get some extra plastic black push pins and don't worry about saving the factory ones! Got mine Line-X and had about half of them I put back with new ones. Once you pull out the black push pins they should pull straight off to the side. Get the 15ct from your local auto store well worth going back with new.
Simple black push-pins commonly referred to as "Christmas Trees"? You're truck must be special, because mine have stupid ridiculous yellow, grey and black clip type things holding them on.
I tried to track them down at the dealer with a part number and they couldn't even get them. I have a picture saved someplace around here, but with everything packed up in my move -- I don't think I'll be able to get it.
The easiest way I personally did it was for the front; remove the front first and then stick your hand and then whole arm up and around the top, feeling and pressing the clip together and popping it out of the hole that the flare attaches to.
Same for the rear, but I started at the rear.