Sign in to your Google Account
Go to myaccount.google.com
Select Data & privacy
Scroll to Data from apps and services you use
Select Download or delete your data
Choose Delete a Google service
Sign in again if prompted
Find Gmail and click the delete icon
Enter an alternate email address for other Google services
Verify the alternate email address
Check the confirmation email
Follow the link in the email to confirm deletion
Review the warning and confirm
Complete the deletion process