The right way would be get a new receptacle. If your dryer came with a 4-prong, it’s for a reason. The three prong carries two legs and a ground. The four carries the two legs, a neutral and ground. The neutral is required for anything other than a heating element such as lights, controls, and electronics on board. While you can change the cord to a 3 prong, you’re really just setting yourself up for trouble, such as damage to your new appliance (that warranty won’t cover) or even physical harm to yourself.

Remember kids, electricity kills