Start out by gathering up everything needed to make this cocktail.
Toss some ice into the highball glass. It should be filled about to the top with ice.
Pick up the rum and jigger. Measure out 2 oz of rum with the jigger. Then, toss the rum into the glass.
Pick up the grapefruit juice and jigger. Measure out 4 oz of grapefruit juice with the jigger. Then, toss the grapefruit juice into the glass.note: instead of measuring the grapefruit juice, you can just pour it directly into the glass and top the glass off. To mix everything together, there are two options:1) Put the bar spoon into the glass and stir well.2) Carefully toss the drink from the glass into the shaker. Then, toss it back into the glass.