This is from my mother-in-law's doctor, so it's not just a folk remedy. She had a heel spur, and I had a spur in my heel and in the ball of my foot and it worked for both.
In the morning before getting out of bed, lie on your back and bend your toes toward your head holding as long as you can. Do this for about ten minutes, doesn't have to be ten continuous minutes though - just hold as long as you can, relax and do it again - up to ten minutes. When you get up, don't go barefoot, even to walk to the kitchen. Wear a shoe with a gel cushion in it; they can be found at any big box store or drug store.
Three times each day (and meal time works great) get an ice pack or a bag of frozen peas, put it on the floor and place the area of your foot with the spur on it. Roll it around on the ice for 15 minutes. Frozen peas work great for this because they are rounder and therefore less painful than ice, and they don't thaw in the 15 minutes they are out and can be reused indefinitely.
This is not a quick process, depending on the severity of your spur, it could take anywhere from three to nine months, but it does work.
Until next time, may you have blessings and relief from heel spurs,