How do I change a 3 wire outlet to 4 wire outlet?


You don't. There are only 3 wires in the box, while a 4 wire outlet requires 4 wires. All new wire would have to be pulled from the panel into the outlet box.

Updated on January 8, 2018

Original Article:

Changing a 3-Prong to 4-Prong Dryer Plug and Cord
By Dan Harmon