I am removing the tub/shower from our master bath (ground floor; slab foundation); replacing the shower/tub with a luxurious shower. The copper supply lines need to be moved 18 inches to accommodate the new shower. The supply lines are in slab. If the answer already exists in the forum, please indicate. Otherwise, please provide direction on most practical way(s) to relocate the in-slab 1/2'' copper supply lines.

Hey Smitty,
I don't see where you have any options but to open up the slab wth a cement saw, bend the soft copper over under the slab, run 18 inches and bend upwards out of the slab sleeving the copper with Armoflex all the way under the slab and a few inches above the cement patch you'll have to make.
My code frowns on joints under the slab so instead of using a solder or Sharkbite fitting to make the bend go to a Plumbing Supply House and purchase a 1`2" bending spring, (see image) and a ;5 foot length of Armoflex, (see image) to protect the copper. Good luck, Tom