#1 - The T50 Torx bolts do not come out easy if it's your first time taking the hinge off. It looks like the factory puts some blue lock tight stuff on them. What you can do is spray the ends inside the tail light compartment with some DW40, You can use Liquid Wrench or some other brand of penetrating oil. Then try to unscrew them until they get tight again, then spray the Head side of the bolt and screw them pretty much all the way back in, finally spray the end in the Tail Light compartment again and repeat this process until get them out.
Also, We would recommend that you leave both bolts in until you have them both loose enough to remove both at the same time. So if you get one completely out, put it back in all the way until you get the other one loose all the way. Once both bolts are loose you can remove them both very easily.
#2 - The Tail Light - Once you remove the two smaller screws in the tailgate side that hold the tail light to the truck.. there are three connection points for the tail light assemble .
There is point on the very back top of the assembly as soon as you pull the back of the light, you can see the hole where the first point goes in, so make sure you pull back a little on the back of the tail light so this point disengages.
The other two points are on the far side of the tail light assembly, so once you clear the back point then you want to remove the assembly by slowly pulling it backwards. If your tail light assembly felt like it was sealed with something all around the perimeter, so you have to work it slowly by wiggling it, you could hear and see the seal being broken as you wiggle it. The seal broke from the back of the truck and then slowing around the top and the bottom and around to the front. Once this seal was broken the assembly was very easy to pull back and then undo the plug. When you go to put the tail light back in place make sure you line up all three connection points. Look at the back of the tail light assembly and you will see the two points top and bottom on the front of the assembly (on the part of the assembly that is on the side of the truck and furthest forward.
The other connection point is the first one I described above, on the back and top of the assembly. Make sure all three of these connection points are lined up before you try snapping the light back in place. If you are having issues getting the screw holes to line up, it might be because you don't have the connection points in the right place.