Follow these steps…
Put the four lime wedges into a glass
Add the sugar and muddle (squish everything together) to release the lime juice
Put the mint leaves on one hand and clap. This bruises the leaves and releases the aroma.
Rub the mint leaves around the rim of the glass and drop them in. Use a muddler, bar spoon (or even a rolling pin) to gently push the mint down into the lime juice
Half fill the glass with crushed ice and pour in the Bacardi Superior rum. Stir the mix together until the sugar dissolves
Top up with crushed ice, a splash of the club soda water and garnish it with a sprig of mint