It can be raised from seeds sown in early spring as soon as they ripe but the easiest way is to root leaf cuttings at 24-27 Celsius degrees (75-81 F) at any time of the year. Cut healthy leaves from the parent plant. Put the leaf into a glass of water inserted through an aluminum folio, the one that you use in the kitchen, that is placed over the glass. Make sure that the base of the leaf is in water. It will root in few weeks, after that you can plant it.
You can also insert each stalk in a small pot of cutting compost so that the leaf blade is just clear of the compost. Water and cover the pots. Small cloches made from the bases of plastic drink bottles are just fine. Leave them in a warm place, in good light but out of direct sun.
Each leaves should produce several plantlets. When these will develop enough you can remove the covers and grow them on until they become large enough to pot up individually.