One thing for sure….don’t force them using the knobs in the cab. You can pull the handles right off. As described above soak them over there entire length even if you do not remove them from the truck you can still spray them over their entire length. Another trick is to gently bend the cables everywhere you can in all directions this will slightly open the wound wire cover and help free the inner wire. And of course be sure whatever they are connected to is free to move. You may want to grab the inner wire at the carburetor end with something like vice grips so you can pull from that direction.
