You can reheat Christmas puddings using one of the following methods:
To reheat in the oven, remove wrappings from the pudding. Wrap in foil and reheat at 300ºF (150ºC) for an hour or until hot.
To reheat on the stovetop, remove wrappings and place the pudding in the original mould. Cover tightly. Set pudding mould on a trivet in a large saucepan and steam 3/4 - 1 hour or until hot.