Considering my sink is on an exterior wall and my hot water heater is in the attic would you suspect both the hot And cold lines drop from the attic and down the walls? My biggest fear with this is that the cold water line goes through thr slab for some bizarre reason.Well since I don't know your layout I can't say if that would be best. If you do it that way you'd likley need a place for it to go.
The best would be of you could cut near the plug and push it the toward the cut. That could back the plug out.
All of this is actually very dependant on the piping schematic.