Transplanting a Christmas cactus plant is a relatively easy process that can be done at any time during the year. To begin, carefully remove the plant from its pot and gently loosen the soil around the roots. Then, using a garden trowel or shovel, dig a hole that is slightly larger than the root ball of the plant. Place the plant into the hole, backfilling the hole with soil and gently tamping it down around the plant's roots. Water the plant well after transplanting, and keep the soil moist until the plant has established itself in its new home.