Left click on Person/Org menu option.
Select the person you would like to delete by using the Drop-down list button 
. Scroll down and left click on the name that you would like to delete. You can also navigate within the list using the up and down arrow keys on your computer keyboard and then pressing enter to display the desired screen.
Left click on 
which is located toward the bottom left side of the screen.
A dialog box will be displayed which will ask you to either left click on the OK button 
to delete this person or on the Cancel button 
if you choose not to delete.