Flooring Tile - Retiling Shower Floor

I am considering retiling my shower which consists of tile laid on a mud bed and lead shower pan.

Is it possible to remove the tile from the existing mud bed and just retile over it? Or would it be better to rip everything out and start from new? I am also concerned about the shower drain and whether that would need to be replaced if I have to remove the existing mud bed. The house sits on a slab and has old cast iron pipes (early 1960s vintage)that makes it a big pain to replace. Any suggestions?

The pros that do tile work everyday may disagree with me, but considering the age of the shower, if I was going to tear into this shower, I'd rip it all out and start over from scratch. Yes it is possible to retile over the existing material, provided that all is currently well with the existing tile, (no loose tiles, no leaks in the pan, etc). I think you will find it pretty difficult to just remove the tile from the mud bed without doing significant damage to the mud bed. Just my .02¢ based on past experiences with such situations. Hope that helps a little.

I completely agree with that advice. You will probably also find that the cast iron drain pipe in the slab is tremendously corroded. Start hammering away, if you are uncomfortable with redoing the drain connection, have a plumber come in after you open the slab and replace the trap and stub out the drain with 2" pvc. Then you can install your pvc clamping drain with a presope and liner. I stay away from cast iron drain work myself, but once the drain is redone with pvc then it's pretty easy from there. I'm sure you could be walked through the drain part if you post that portion in the plumbing forum and pictures would help a great deal there I'm sure. Once the drain stub is set and the slab is patched, come back and we'll get you through all the framing, pan, curb, walls and tiling details.