You can knit over to the column of sts above the mistake, drop the next st and then let it ladder down to the mistake. Fix the sts that are wrong and then continue to ladder up (like a dropped stitch, here
) to the working needle. Repeat that for the next stitch and all of the columns above the mistakes. If you feel brave, you can let several sts drop off the needle and ladder down but one at a time works too.