In replanting seedlings (pricking off is the gardening term) you must be extremely careful not to damage the roots of the new plant. A good way of assuring yourself that the plants go undamaged is to use a notched planting stick to prick them off. The soil in the pot should be dampened to receive the new plant and should, again, be tamped down. The pot should be provided with good drainage material at the bottom, and filled with your regular potting soil. With a dibble, or a sharp pencil, make a shallow hole in the soil, and set the plant in it, pressing the earth back around the stem with your fingers. It should then be thoroughly watered, preferably from the bottom, and kept for a day or so in a shady corner.