Summarize the following:
If your clay is only slightly hard, you may be able to soften it just by warming and kneading it with your hands. Before you start kneading the clay, hold the clay in your hands to warm it. You can also warm it using the heat of your body by sitting on top of it.  Warmth helps to revitalize the clay. If your clay is only a little bit hard, you may be able to restore its softness just using body heat. No matter what method you use to soften clay, always warm it first. If the clay is especially hard, you may need to use a heat source to soften the clay. Lay a hot water bottle over your clay for twenty minutes to help soften it.  You can also use a heat lamp, but be sure to not heat the clay over body temperature. This can cause the clay to start to bake, which will make it unusable. Additionally, you can put the clay in the microwave for 10-second spurts until it is warm. Once the clay has softened, roll it between your hands in a snake shape, then roll it into a ball. Rolling the clay creates friction, which helps to soften it. You can also cut the clay into small pieces, then roll it. If the clay is still too hard to roll with your hands, you may need to use more force. Lay the piece of clay on a clean cutting board or on the counter, then press down on the clay to flatten it out as much as you can. Then roll the clay out with a rolling pin. After you roll it out, it should be warm enough to roll with your hands. If your clay is too hard to roll out with a rolling pin, you will need a large amount of force. Break the clay up into as small of pieces as you can, then place the clay pieces in a sealed plastic bag. Wrap the bag with a cloth and put it on the floor or on the cement or pavement outside.  Use a rubber mallet to pound on the clay for several minutes. Using the mallet will break up the clay and add friction which will make it softer. After you have used the rubber mallet, take the clay out of the bag and roll it with your hands into a ball. After you have rolled the clay, knead the clay with your hands on a counter just as you would with dough. Use as much force as you need to pull apart and reshape the clay.  Kneading the clay ensures that you handle the entire surface area of the clay. You can also use a clay-kneading machine if you don’t want to knead by hand.

Summary:
Warm the clay with body heat. Warm the clay using a heat source. Roll the clay in your hands. Roll with a rolling pin. Hit the clay with a mallet. Knead the clay.