mosaic tiles

Hi All I need to remove the mosaic tiles (attached) and replace with a standard tile. If I remove the tiles, I am most likely going to have to break the plaster board behind, how do I refit the plaster board to the gap? Sadly there is no stud wall behind to support the new plasterboard Thanks

Would greatly appreciate some advice on a first ever tiling job (albeit a very small one). Bought two 30x30 natural stone mosaic tiles from B&Q to form a splashback over a 42cm wide cloakroom basin, along with a tub of Mapei wall adhesive and grout (yes I know the sticky advises against such...

I am determined to stick a row of mosaic tiles round my shower area as a border between rows of ceramic tiles. I have several problems. 1. The ceramic tiles are 9mm thick and the mosaic tiles are 8mm thick so, even if I put more adhesive on the back, all that happens is that more of it squeezes...