Go to your Google Account page: https://myaccount.google.com/
Sign in to the account you want to reset
Open Security
Select Password
Enter your current password
Enter a new password
Confirm the new password
Save the changes
If you forgot your password, go to https://accounts.google.com/signin/recovery
Follow the account recovery steps
Verify your identity using the requested method
Create a new password when prompted
If you want to remove the account from a device, open the device settings
Go to Accounts or Passwords and accounts
Select Google
Choose Remove account
Confirm the removal
If you want to factory reset an Android device, open Settings
Go to System or General management
Select Reset options or Reset
Choose Erase all data or Factory data reset
Confirm the reset
Sign in again after the reset if needed