Cut the top off the pineapples about 1/2" down to create a 'lid', then hollow out, putting the flesh to one side

If your juicer has a frozen attachment add this now (if not you'll need to freeze once juiced for about 25 minutes to create a slush). Juice the pineapple flesh and the lime together. 

If creating alcoholic version add the rum and the juice into a shaker - a Boston glass works best and serve. Garnish with a pineapple chunk