What does "walk through" mean?

Perform in a perfunctory fashion, as in She was just walking through her job, hoping to quit very soon. This idiom originally referred to practicing parts in a play at an early rehearsal. It was applied more broadly from the late 1800s. Also see go through the motions.

walk someone through. Instruct someone carefully, one step at a time, as in He was very helpful, walking me through all the steps in this complex computer program.