Slide your ZZ plant gently out of its pot. Loosen the roots so that they are not girdling the root ball and will grow in an outward direction. Release any old soil from the root ball and set it aside briefly.
Mix up a fresh batch of well drained soil for your ZZ plant with three parts good quality potting mix and one part sharp sand or builders sand to increase drainage capabilities. Fill a shallow pot with drainage holes partially full with the new soil mix.
Slide the ZZ plant into the new pot or ground location, gently splaying the roots throughout the soil. Ensure that the soil level stays consistent on the stems of the plant. Fill soil in around the roots, pressing gently with your palm to lightly compact. Water in well til consistently moist but not soaking wet.
https://www.gardeningknowhow.com/houseplants/zz-plant/caring-for-zz-plant.htm
