You can soften it by microwaving it for a few seconds.
f you don’t have a microwave, you can put the Play-Doh in a saucepan and heat it until it’s soft, but make sure to stir often so that the Play-Doh doesn’t stick to the bottom of the pan and burn.
You can also try this method:
1. Mix 1 tablespoon of salt in a cup of water and stir vigorously.
2. Submerge the Play Doh into the solution and knead for 10 to 15 seconds.
3. Squeeze and flatten Play Doh to shape it back into a ball and use!
So this is how to soften Play Doh.