Every Android device has a Google primary account. This account allow you fast access to all your Google apps and services. In some instances you might want another account as a primary Google account.
It’s actually not that clear on how you do this, other that doing a factory reset, which will wipe the device. A simple solution for you, would be to clear the app cache from Google apps and services and then you can go about creating a new account.
There are two methods you can use to delete your primary account data. The first involves deleting the cache from all your Google apps and services, but this takes time and you need to know which app data to delete. The second option is documented below, and is by far the easiest to use:
Go to > Settings icon > (scroll down to Accounts) > Tap Google icon, then the email address associated with this account. You should now see the following list of options linked to your account:
App Data; Calendar; Chrome; Contacts; Drive; Google Photos; Google Play Books; Google Play Movies & TV; Google Play Music; Google Play Newsstand; Google+; Google+Photos; Keep; People details and Sound Search for Google Play.
Now tap the > Settings icon (top right) and tap > Remove account. You will now see a prompt “Removing this account will delete all of its messages, contacts and other data from the phone!”. You have the option to Cancel or Remove account.
I’ve tested the above on a Nexus 5 and Nexus 7 running both Jelly Bean and KitKat latest versions. If you notice anything different on other Android devices such as Samsung or HTC, please let me know and I will edit this post.
Safe surfing folks!