I broke my left arm humerus bone in half right below the ball that goes into the shoulder socket. It was major surgery to have an metal rod inserted all the way down from my should socket almost to my elbow. I had to have that rod in there for 6 months. (as a matter of fact, Charlie Waters broke his in almost the same place).
Anyway, after 6 months or so, I went in to get the rod taken out of my arm and all the doc had to do is make a small incision about this long "--------" on top of my shoulder and just pull the rod out. After about 6 stitches or so...I was good to go.
So, saying that, making some really tiny cuts to take out some screws would be no big deal...it's not like you have to be put under even. it probably took 1/2 hour.