specifically on my gibson sg special?
use a little wooden block and a hammer and tap it out... may need to score the finnish around it first to prevent chipping in some cases..
all you do is use a little block of wood and hold it against the nut angled from the fretboard side and tap the wood block with a hammer to break the glue under the nut.. just tap it back... it will not take much to get it out...
sometimes i was a 4inch piece of drowl rod for taping out nuts
Find an old paint brush with a 2.5" to 3" width and a wood handle.
Remove the steel wrap and bristles.
Put the wide end on the nut and pop the skinny end (handle) with a mallet.
Yes, it is make your own tools time!
you can use anything really... it's just using a soft smooth piece of wood will be less likely to cause any real damage if you slip..