[quote name='Ou7shined' timestamp='1377812803' post='2192391']
If it's safe to do so without singeing anything, you could try holding the tip of a soldering iron on it for a bit to expand the metal.
[/quote]
Thanks matey, it's a bit too embedded in the end of the neck for that I think
I did find this:
"Loosen the strings, or take them off.
Loosen the truss nut if you can.
If not, put a drop or two of PB Blaster penetrating oil on the truss nut, let sit for a day.
If the problem is the truss itself is seized inside the neck, you'll need to loosen the truss all the way, stand the guitar on it's head (assuming the truss adjustment nut is inside) and put a few drops of (or a very short spray) of silicone lubricant so it runs down (up) the length of the truss inside the neck.
Let it stand up (or stand on it's head) for a day.With the truss relaxed inside the neck, the silicone should coat the truss and truss channel, and free it up.
Sometimes it's a matter of the truss being improperly installed."
Thoughts?