How do I change the 4 prong outlet for my dryer to a 3 prong outlet? There is no place for the ground to go.

DO NOT change the receptacle. Change the cord to a 4-wire.

The receptacle dictates what cord is used, NOT the other way around.

I agree with Stan!

Just to add my .01:
The year your wiring was installed was never mentioned, so it may be a good idea to make sure the dryer receptacle outlet has four conductors. You never know>>> Meaning: The amount of conductors ran will dictate the device, while as Stan said, the device will dictate the cord.Warning: Turn the power off before checking for four conductors.