One is to load a square prop, parent everything to the square. Then scale the square, everything else should scale with it. Last, from the squares Properties make it invisible. If you only need to save as a pz3 the above method is fine. Or you could download the MinFig cr2 from the Free Stuff, and parent everything to that. The advantage is that if you then resave MinFig to a figures pallet with a new name, all the figures and props parented to it will save with it, and you can load everything into your document all at once, at the right scale. Min fig its self is invisible, and at under 5 KB file size very small.