Tap the Home Button
> Apps 
> Gmail 
> the Accounts
and labels icon 
(at the upper-left corner of the screen).Tap Settings.
Tap General settings to change the settings for all accounts.
Tap the Home Button > Apps > Gmail > the Accounts
and labels icon (at the upper-left corner of the screen).
Tap Settings.
Tap General settings to change the settings for all accounts.