I have been growing pineapples from tops for about 3 years now. They keep on dieng, but thats usually because I let them see some unexpected cold weather. But they are really easy to root. I take off the pineapple top, strip a good amt. of the lower leaves, and put it in water. It usually gets some roots in a week and is ready for planting in 2 weeks. It should fruit 2-3 years after rooting.

Good luck!