This Snowman looks like one I dreamed of making as a child - he looks very dapper in his scarf and beanie, and really quite content!
The decals should be fired at full fuse temperature or at slumping temperature for float glass.
NOTE: AREAS ON THESE DECALS WHICH APPEAR WHITE ARE, IN FACT, CLEAR, SO FOR BEST RESULTS, FIRE THE DECAL ON A WHITE GLASS, RATHER THAN FLOAT GLASS.