I had all of my wires removed in outpatient surgery. If it had been one wire they would have used local with sedation, but with all, they decided to use general. I went back to work the next day, which probably wasn't a wise idea, but I made it. I went in thinking I was having one wire removed and ended up with all because the xray showed several that had turned. If you already have a vertical scar, they will probably make a small incision on that same scar above each wire that needs to be removed. My scar is horizontal, so they made a small (1 - 1.5 inches) vertical incision between my breasts and removed all the wires through that. I had to go on Lovenox before the procedure, back on Coumadin the night of the procedure, frequent testing until I was back in range.
It's really not a big deal. The worst part was the bruising (my entire chest turned black) and the incision leaked for quite a while (3-4 weeks).
To be clear, my pain was not general sternum pain. It was very clear that it was related to the second wire. When a small child would sit it my lap (I taught first grade) and lean their head back, I'd get a shooting pain, when I wore a sweatshirt with a heavy patch or embroidery in that area, it was uncomfortable, when I'd sleep on my stomach I could feel it, I could touch the area and feel the wire tips. It was also scratching me from beneath the surface, causing bruising.