For the syrup, take out a bowl or food saver bag and add each ingredient as you go along. First, chop up some fresh pineapple into chunks. Then use the edge of a spoon to peel back the skin of the ginger until you have a good sized piece exposed. Chop off the section and mince it up.
Next, peel off the top 1-2 layers of the lemongrass. Then, lay it down on your cutting board and bang the back of your knife blade along the stalk, to release it's oils. From there, chop off the woody end where the root was, toss it, and grate the remaining stalk until you hit leaves that are too soft to grate. Chop the rest, on the bias, into thin slices. Repeat if necessary until you have the correct weight.
Now, gently peel the limes and orange with a y-peeler leaving as much pith behind as possible.
Once those ingredients are in your bowl or bag, add the sugar and mix gently until the sugar becomes sandy in texture. Then, leave it on the counter or in your refrigerator overnight, mixing and gently mashing every few hours to make sure the sugar is uniformly coating and breaking everything down. The next day, strain the syrup through a fine mesh strainer, into a lidded container, and keep it chilled until you are ready to make the margarita.