It is possible to replant a Christmas tree without roots, but it requires some special techniques. First, you need to cut off the top of the tree and remove any dead or diseased branches. Then, you need to dig a hole that is at least twice as wide as the root ball of the tree. Next, you need to add some compost or soil to the hole to help the roots grow. Finally, you need to water the tree regularly and make sure it gets enough sunlight. With proper care, your Christmas tree should be able to grow roots and survive in its new home.