It sounds like one of the control rods has fallen off the release arm of one of the latches. You will need to remove the door panel from the inside here is a guide to help you get an idea of what you are in for.
The rod the the handle pulls on to unlock or release the trunk latch. It may have become disconnected and needs to be re-connected.
If you can get to the latch from the inside there should be an, "Escape or Emergency Latch Pull", that is required in vehicles since 2002.
I am not sure if it is required in trucks, but most NHSTA safety requirements are for all vehicles. If you do not have one you may be able to unlatch it by grabbing the rod, some trim panels may have to be removed which are held in place by number two phillips screws and body plugs which pull straight out just be gentle with them, and pulling on it where it should be pulled on by attachment to the handle.
It may be difficult to get to as some trim pieces may be held in by the fact that the hatch is closed. You might have to carefully work them out or work under them with them partially attached. The latch is at the bottom, so hopefully there is an escape or inner release that will make it easier.
The latch can also be released if you can get to the latch key which is a flat plate right next to the latch plate which grabs the U-Bolt that holds the hatch in place. This is the part that the emergency release and the handle release rod are attached to. So, if you can move it with a flat bladed screw driver the latch will come open.
The important thing is not to use excessive force while doing any of this as everything does not take much force to actuate or when removing trim parts they do not take much to pull off. If you have to force it then something is being done incorrectly.
Here are some diagrams (Below) to help you see what Im talking about.
Please let us know if you need anything else to get the problem fixed.
Images (Click to enlarge)
Saturday, October 21st, 2017 AT 2:00 PM