i would open it in max or some other modelling software, and unwrap the die so that all the faces can be seen on a single plane, planar map it so that there isnt any distortion, and then morph it back into its original shape while maintaining the same uv coords and export it back out as obj. Alternatly, if you have uvmapper pro, you could just select each face individually and apply a planar map to each individual side, then just line them up on your template.