One thing that that works 75% of the time is to take a straight pin and "work" on the scratch. If it is skipping you have nothing to lose.
You should wash the vinyl with a toothbrush and mild soap. If after scrubbing the record it still skips, keep playing it on the turntable, watching it closely, while trying to find out exactly where the skip is occurring.
Then take the record and under bright light, look to find the problem area. When you do, take a straight pin and slowly work on the scratch by going with the groove. Work on it for awhile and then try playing the record. Lots of times it takes a few attempts to get it to play through. A lot of times there is some residue noise left over at the spot that was worked on.
Now, if it is a perfectly lateral scratch that doesn't cross the groove but runs along inside it, youre out of luck, but once in great while you can fix it.