How do you change 110 volt washer wall plug to 220 volt wall plug?

You don't. Voltages are a nominal rating. 110 volts is within the nominal range at this potential. The voltage centre line is 115 volts. Utility companies are mandated to keep voltages locked within 5% of a centre line voltage. This means that it could be as high as 115 + 5% = 120.75 volts and as low as 115 - 5% = 109.25 volts