How do I replace the grout line where the floor meets the wall in a tiled shower stall? What is the easiest way to remove the old grout with out scratching the tiles? Could I use a waterproof latex/silicone caulking in the horizontal line instead? Thanks for your answers in advance.

There are several tools for removing grout, some cheap others not. Here is one I would not try YouTube - Grout Grabber Grout Removal Tool But for only a few bucks this works too. Trowels

You can use a very small chisel, a grout saw, a cut hack saw blade, a diamond blade in a Dremel or other cutters. Do not use LATEX silicone, use full silicone. You will need to clean the joint, acetone works pretty well, and then caulk. Use blue masking tape to form a straight line, caulk, smooth with a wet finger, let set 4-5 minutes and remove the tape. Do not use the shower for a day or two.

The removal of the grout is just a lot of work. As others mentioned, there are a jack load of tools that are made. One additional suggestion, most grout manufacturers make a siliconized grout. It comes in either unsanded or sanded and someone will make it in a color that matches the color of your grout. These look better than a standard silicone and will hold up just as well. Expect to have to clean and regrout this type of joint every couple of years as expansion and contraction effects these areas substantially.

Yep. Welcome to AMHD, Brian

Thank you very much, I have enough information now that I am ready to jump in and give it a try. A hand chisel first and see if that goes easily enough on the 14' or so of grout line. The shower has been drying out for a couple weeks so it is time to get going on it. Aloha to you all.

Shell

OK glad we could help. One word of caution, a chisel is the least effective tool of all the ones we listed. It can easily chip the glazed edges of the tile unless you are very careful. A grout saw or Dremel tool are much easier to use, more forgiving and much quicker, unfortunately they are also more expensive