How do I change an email address of a contact?

In the version that I had.  

Click on the Contact Icon on the right side of your email 

screen.   

Scroll down to find the Contact your want to change. 

(Unless you have a glob of contacts, then I would use 

the search function to find the contact you want) 

Click on that Contact.    

Then,  the Contact details come up.  

Then, left click on the "..." (Three dots) at the top

of the details screen.

Then, select "Edit" from the menu which appears. 

Scroll down to the email field . 

Backspace over the previous email listed 

(if there is one)  to erase it 

Then, enter the corrected email address.   

Click on "Save" at the bottom of the editing screen.