Sign in to your Google Account
Go to myaccount.google.com
Select Data & privacy
Scroll to Data from apps and services you use
Select Delete a Google service
Sign in again if prompted
Find Gmail and select the trash icon
Enter an alternate email address for non-Gmail Google services
Verify the alternate email address
Follow the on-screen confirmation steps
Confirm deletion of Gmail
Check the alternate email for the confirmation message from Google
Open the confirmation link in the email
Complete the final deletion confirmation
Save any important emails before deleting
Remove Gmail from devices and email apps after deletion