Removing of "scratch sound" from guitar recording?

The only way to fix it that comes to mind would be recording it more carefully. Try to add some kind of lubricant on your strings.
 
^^Actually, I was joking.

On a more serious note, the only thing that I can think off (aside from pulling out the scratchiness by using surgical narrow cuts) would be to try chaining an extreme low pass filter (something at like 4-5 kHz) with hi shelf/peak filter, which would be used to boost frequencies beyond the LP's cut off point, in order to compensate for the loss of hi freq content.
But the OP should really post a clip which shows the problem, because atm we all are just theorizing on the subject, rather than solving it.
 
haven't used that izotope rx before, but the de-esser trick that was mentioned can definitely help to reduce string squeal

i also have heard of people doing what uros mentioned - copy the track, bandpass it so that you only hear the squeaking, then flip the phase. this should cancel out most of the noise, but seems like it might result in some sort of weird artifacts and the such

in the end, the best thing to do is to play the part without the string noise in the first place...
 
That usually comes down to a bit of lazy technique. You'll obviously have a bit of that no matter what, but I usually have no problems just automating it down a little in volume. If it was that bad, I would have had them try again.
 
the worse shit to me it´s the noise that comes from changing from a chord to another. In those cases I edit to the hell and back.
 
I actually often have the opposite of this problem. I wind up making so many mid-range cuts I wind up losing my pick attack.