When I try to open the tailgate, it doesn't work unless I pull handle and stick skinny flattip on pass side lock tab and pull up to drop tail gate, how do I get in tail gate to adjust it?

 

On the other side of the tailgate (behind the handle), there is a panel with 4 screws. Removing the screws will give you access to the linkage.

You might need to adjust the striker (the thing the latch, well, latches onto). It's adjusted by loosening the torx bolt in the center of it, and moving the striker as needed.

 

Oh I got bed Liner, can't tell where screws r

 

Try cleaning and lubricating the latches first, I've found they get dirty and won't fully disengage.