If you just want to add another account, check out the article How to Add Personal Data to Another Account Correctly
Step by Step
Access your account through the browser.
Go to Account Settings.
Click on Remove.
Confirm the action.
IMPORTANT: Once completed, the previous data is unlinked from the account and cannot be used again with another email.
What to Avoid
Do not remove the data before adding new ones if you want to reuse Picnic.
Do not remove the data to correct errors.