Contact Card is the place where you can edit all lead information, and it's accessible from two pages.
Primary access is from 
Global Data → Any of the sections, by clicking on the card in the Contact column.
but alternatively, you can access it from 
AI Scheduler → both Upcoming and Past tabs as well.
Simply locate the contact, expand the call details and click on the email to access the contact card.
Once Contact Card is opened:
Click on the three dots and select "Edit" button
New window will appear from where you:
can edit primary information, such as Name, Email, Phone or
select secondary information, such as secondary email or phone
Learn more about Contact Cards here.