Cut the pork in half, rinse, and drain well. Place in a large bowl.
In a small bowl, combine rock salt, ¼ cup of brown sugar, and Prague salt. Stir until evenly distributed.
Rub curing mixture on the pork, massaging well to coat. Transfer pork to an airtight container.
Cure pork for about 5 to 6 days, turning on sides every day. Rinse and drain well.
Place on paper towels to remove excess liquid. Place the pork in a meat net and tie the net tightly to form the pork into shape..
Place the pork in a large pot. Add pineapple juice and 2 ½ cups of brown sugar. Stir until sugar is dissolved and bring to a boil.
Lower heat, cover, and cook for about 1 to 1 ½ hours or until meat is tender. Remove the ham from the pot and using scissors, cut and remove the net while still hot.
Allow to cool and then rub with the remaining ½ cup brown sugar.
Arrange in a single layer on a baking pan and broil until caramelized.
Meanwhile, boil the pineapple and brown sugar mixture until thickened.
Slice the ham into desired thickness and serve with the pineapple glaze.