Choose a short passage
Pick a measure or two that needs attention. Check the notes and fingering, then play slowly enough to notice what your hands are doing.
Change one thing at a time
If the rhythm is uncertain, count it aloud. If a note keeps slipping, check the fingering. Work on that one issue, then play the passage again and listen for the difference.
Put it back in the piece
Play the measure before your passage and continue through it. This helps you move in and out of the part you practiced without stopping.