To remove a nut:
Gather the needed tools...
1/4 wood chisel (or thin slotted flat screw driver)
small strip of fine grit emery cloth
toothbrush
Clean area completely.
apply a focused mist of steam (teapot) to the nut for 20-30 seconds. Do this by holding the nut (flip your guitar belly up) in the mist for the half a minute. Do not steam it long or you can jack up your finish.
hurry hurry.. lay the guitar on a table and gently ease the edge of the chisel under the nut. Wiggle it in SLOWLY.
If its going great then go all the way through. If it gets harder to lift the nut, re-steam and give it another go.
let it sit for a minute then swipe the emery cloth in the seat a few times to clear off the extra glue. Don't get crazy, you are just removing the glue, dont sand any wood off.
Toothbrush out any mild dust that remains.
Tada... ready for new.
second means to remove nut:
Try to lift a Chevy 350 alone.