You can cut off the crown on the top of the fruit. (See above photo) Its easy and available, but the bad part is that it could take two years before it flowers and another six months before the fruit is ready to eat.
You can also use the shoots that grow off of the sides of the fruit, if you happen to find them, which will be more likely if you buy locally grown pineapples as opposed to the commercially grown ones. Planting these slips will cut down your waiting time.
The quickest way to get fruit is to use the shoots that come of the main stem. You’ll need to have your own garden to get these slips that are also known as suckers. You can then either cut them off and replant them or leave them on the original plant and let them grow.
Apparently pineapples can also be grown by seeds, which are sometimes found inside the fruit. Personally, I don’t remember ever coming across them as they are not often found in commercially grown pineapples.