This would be difficult with so many voids, some of which appear to be almost touching. In general you'd look for symmetry first so as to reduce the model size, and then to look for voids on the same plane to ease partitioning. Even if you were able to partition the cube shown in the picture successfully, the result may be that you'd have invalid elements of poor shape. For this case your best option is to use high order tetrahedral elements.
