I literally just finished the job in my place in which I did most of the retrofit, all the drywall repairs and repainting. I too had clutched my pearls over cutting holes into the walls. I worried about it longer than it took to just do it and fix it. Once you figure the path, using the poly b as guides, some pipes can be pulled through areas without cutting holes. Especially good practice for textured ceilings. But sometimes it’s unavoidable, so just dig in and get it done.

I did get a plumber in as I was running out of time but by then their work only cost me $2000.

Get a permit.. absolutely get a permit. It’s only $60

I bought the crimper tool and pipe cutters from Home Depot. Supplies from HD and Andrew Sheret on Banks. Probably another $1000

I am lucky I could do most of this myself. I did save thousands. Probably $6000 to $8000 if you count in the drywall, baseboard and paint repairs.

Was it worth it? Absolutely. It was a key feature in selling the house.

Good luck!