Click the My Orders tab on the left side of the page

Click the gear icon for the order you would like to change and select "Change Order"

Select "Switch to a different event"

Select the event you would like to transfer to

Click "Edit" for the ticket you would like to transfer to a different event

Select the ticket type from this new event that you would like to transfer to 
*Please note that you will be charged for any difference in price, requiring you to enter in your card information.  If you are changing to a cheaper ticket, you will not be refunded the difference.

Fill out any required information and click "Update Information"

Click the Pay button at the bottom of the page, which will tell you your total (if applicable)