Cut the top off of the pumpkin and leave yourself about an 8" diameter hole. Scoop out the insides. Place a small vase or plastic container inside the pumpkin to hold the water for the flowers. Arrange your flowers.
The whole process ended up taking about 30 minutes. I think I'll end up going back to the floral shop and adding some olive branches and more hydrangea blooms closer to the holiday,for a soft green touch- but I like where it is going.