https://support.google.com/device-usage-study-help/answer/15453809?hl=en&ref_topic=15453522
Manage your account settings - Device Usage Study Help
To change the email address that you use for the study go to the study portal. Add Google email accounts You can add Google email accounts that you own to the...
manage your account settingsdeviceusagestudyhelp
https://support.google.com/merchants/topic/12564660?hl=en-IE&ref_topic=11983022
Manage your account settings - Google Merchant Center Help
manage your account settingsgoogle merchant centerhelp