Shovel snow with a non-metalic shovel. Sharp shovels that might chip or mar the surface should not be used. Shovel in the direction of the length of the decking material.
Starting on one side of the deck, shovel a strip of snow, tossing the snow off the edge of the deck. Repeat this, continuing across the length of the deck until snow is removed.
Use calcium chloride or rock salt, available in many home centers, to melt stubborn ice patches on Trex decking. Rinse off when first practical.