I had trouble with those also and I ended up taking the whole front clip off in one piece

 

In the kick area about knee height when seated in the truck is a rectangular hole just in front of the door opening that may or may not have a cover over it with one screw attaching the cover. If the cover is there, remove the one screw and remove the cover and look inside with a flashlight. If no cover then just look inside with a flashlight. It's the same 1/2" bolt head as the other fender bolts. A six inch extension should reach it.