Cut the pineapple into chunks.
Place in a food processor, chopper, blender. I used the Ninja and it really makes a smooth job of this process. Here is a link to the exact one that I have - Ninja Master Blender.
After you have your pineapple all blended - pour it through a sieve. I also rub my fingers around in the sieve and get as much juice as I can. You won't have very much pulp left when you are done. Do not worry about exact measurements.
Pour back into your food processor and add the juice.
Mix again to blend.
Pour into you popsicle molds and freeze at least 6 hours.
You will have a couple of popsicles worth of extra filling. Put it in the fridge and save to make more popsicles after you remove the first set. Or ... drink it as a smoothie. Delicious!
Here is that clickable link for the popsicle mold that I used Classic Pop Molds. I have used them many times and it works really well.
To get the popsicles out of the mold I ran hot water on the sides first. They slide right out really easy.
Take the frozen popsicles out of the mold and put in a freezer bag.
Replace in the freezer.