Have worked w/leather over years as well as having worked on own
garments, etc., making repairs. Hope this might help.
If leather is smooth (not sueded), you can't actually remove a
scratch but you can work on the scratch to blend it into the
leather, smoothing it out again so not so visible.
Use either good quality leather conditioner or matching color
leather cream for this purpose. I chose to use leather conditioner
to work out scratch since color leather cream will create a darker
line once scratch worked out/back into leather. What has happened
is just like when we get a cut ourselves and there's fresh skin
exposed. Either leather conditioner or matching color leather cream
is going to penetrate moreso on fresh leather exposed by scratch to
the leather which is pretty difficult to avoid to some degree.
Apply small amount leather conditioner to scratched area and
work it along line of scratch, gently smoothing out the edges of
the scratch. Safest way to work on smoothing out/blending in
scratch is to work from outside of the scratch edges inward toward
the center of the scratch. What you're attempting to do is close up
the scratch working outwards into the center so that edges of
scratch blend in as much as possible.
You'll get a feel for working on the scratch line and should see
it closing up w/possible exception of fine line in center. You can
then decide if you want to apply matching color leather cream
afterwards to see if covers up scratch further. But what you'll
most likely expexrience is further darkening of your scratch
line.
If garment, etc. is sueded, what you need to do to fix scratch
is use a small wire suede show brush to life the nap up
along/around the scratch line. I start out gently using the little
wire shoe brush to brush up the nap around and along the scratch
line. As you work w/the wire brush you will be able to tell how
hard to need to use the brush on the suede to bring up the nap
again in order to hide the scratch.
Hope this helps.