1. Wear safety spectacles and protective gloves because tiles can break into sharp splinters. Use a drill and a masonry bit to drill a hole in the middle of the cracked tile.
2. Use a hammer and old wood chisel to get the pieces of cracked tile off the wall. Working gently, tap the chisel into the hole you've just drilled and use it as a lever to prise out the sections of cracked tile.
3. Once you've got the bits of tile out, chisel out the old adhesive. Do this by gently tapping and aiming to remove a little at a time. If this is tough going and you have a blow torch, use it to heat up the blade of a paint scraper. Don't use the blow torch directly on the adhesive.
4. Spread some wall tile adhesive on the back of the new tile and press it into position. Getting the right amount of adhesive is crucial; if you use too much glue, the new tile will stick out from the rest. Not enough adhesive will mean it sinks in too far. If you don't get it right first time, prise the tile off straight away and scrape off - or add more - adhesive.
5. Once the tile is in place, push the bare end of a few matchsticks into the grout gap or use purpose-made tile spacers. Wipe any extra adhesive off with a damp sponge.
6. Leave to set and then pull out the matchsticks. Grout in the tile. Use the blunt end of a pencil to push the grout into the gap around the tile. Use a damp sponge to wipe off any grout on the tile.