What method do you use for lighting steps and walls in a masonry application? Do you run conduit? Do you lay the wire right in the mortar? I've done both and in both cases, the wire ends up in the mortar somewhere. Lights have not been such that are mounted into the wall but rather under the caps shinning down. Honestly, I see no issue if it was set completely in the mortar. Why would you need to remove the wire? You might change the fixture, not the wire. Its sealed from the environment too. Like wires in your house walls, they're trapped in there.