No, its not possible to split it - its a shrub, and these can't be split. Cuttings might be an option though - semi ripe cuttings around now, or layer a couple of the lower branches by pegging them down into a pot or the soil - they should form roots after a year or so.

If it is simply too big it can be pruned back very hard. This is usually done after flowering so that you get new flowers the following year. And you can take cuttings off the bits you prune of course.