Sign in to your Google Account
Go to myaccount.google.com
Click Data & privacy
Scroll to Data from apps and services you use
Click Delete a Google service
Sign in again if prompted
Click the trash icon next to Gmail
Enter an email address to use for other Google services
Verify the email address
Check the confirmation email sent to that address
Open the email and click the confirmation link
Read the final warning carefully
Confirm deletion of Gmail
Wait for the deletion process to complete
Download any important emails before deleting
Update any accounts linked to your Gmail address before deleting