You use the scale command. Unfortunately, your drawing is not to scale. When I scale it to be 16" high, the bottom is bigger than 10". This is what I'm attaching.
One way to make it the sizes you need is to make it a block. When you reinsert the block, you can scale each axis independantly.
After rereading your post again, I'm guessing you don't have AutoCAD, right? What are you using to print it? Can you scale it in that?