I've just had to do this so thought I'd give something back for once. It's a horrible job though so if there's even a slight chance you'll have to take a tile off for god's sake get it off while the cement's still wet...
But if like me you don't, this method worked pretty well and left the surrounding tiles undamaged. I hadn't grouted though, it's probably trickier again if you have. Even without it made loads of dust and took ages though. The standard advice of hitting it in the middle with a nail didn't work at all on my tile, hit it very hard with bunch of things and barely chipped it. When marble is bedded in it seemed very tough.
Cover the shower tray with some polystyrene or something to protect it from falling debris. Get a diamond cutting blade; a cheap one will do, then put it in an angle grinder. Cut about 15mm in from the edge, right through the tile, going all the way round the tile's perimeter. Get an old wood chisel thin enough to go in the cuts from the grinder blade. Push it in to the bottom of the tile and wiggle it from side to side until the tile chips off. You shouldn't need a hammer and you're looking to shear it off to the side rather than drive the chisel any further in. Provided you've cut all the way through the tile it should crack off and the grout line gives it space to crack off. Go round and take off this strip around the edge. Then just cut with the grinder and use the chisel to shear chunks off, working your way inwards until the whole tile has gone.
Then you can change your angle grinder disc for a normal (i.e. non-diamond) stone grinding disc and use that to grind the cement off, which is a nasty, messy job and you have to be very careful round the edge not to hit the surrounding tiles, but it can be done if you're patient. you'll definitely need goggles and a mask in a confined space of a shower.
Then you can recement and stick another tile on. But if you can avoid this job, then do, it's one of the worst jobs I've had in a two-year reconversion...
But if like me you don't, this method worked pretty well and left the surrounding tiles undamaged. I hadn't grouted though, it's probably trickier again if you have. Even without it made loads of dust and took ages though. The standard advice of hitting it in the middle with a nail didn't work at all on my tile, hit it very hard with bunch of things and barely chipped it. When marble is bedded in it seemed very tough.
Cover the shower tray with some polystyrene or something to protect it from falling debris. Get a diamond cutting blade; a cheap one will do, then put it in an angle grinder. Cut about 15mm in from the edge, right through the tile, going all the way round the tile's perimeter. Get an old wood chisel thin enough to go in the cuts from the grinder blade. Push it in to the bottom of the tile and wiggle it from side to side until the tile chips off. You shouldn't need a hammer and you're looking to shear it off to the side rather than drive the chisel any further in. Provided you've cut all the way through the tile it should crack off and the grout line gives it space to crack off. Go round and take off this strip around the edge. Then just cut with the grinder and use the chisel to shear chunks off, working your way inwards until the whole tile has gone.
Then you can change your angle grinder disc for a normal (i.e. non-diamond) stone grinding disc and use that to grind the cement off, which is a nasty, messy job and you have to be very careful round the edge not to hit the surrounding tiles, but it can be done if you're patient. you'll definitely need goggles and a mask in a confined space of a shower.
Then you can recement and stick another tile on. But if you can avoid this job, then do, it's one of the worst jobs I've had in a two-year reconversion...
