Hopefully, your pipes are UNDER the concrete, not IN it. Of course, they come up THROUGH the cement.
You will need to deal with the cement, because the tub drain is probably not located where you want the shower drain, and even if it was, it would be difficult to connect a shower drain to an existing tub shoe. You also need to get rid of the tub overflow. When you remove the tub, you may find that this is not as difficult as you anticipate. There is probably a large dugout opening in the slab where the tub waste and overflow piping are. A little slab busting will let you move it to where it needs to be.