There are 3 important elements:
Compulsory - your password.
- Secret Token file
You should have downloaded this file upon your account registration.
If you did not do that, and you still have access to your account, then you can download it from this page: link
- Secret Phrase
It is an optional second password.
To reset your lost password you will need your Secret Token file.
You have downloaded this file upon your account registration.
If you have enabled the optional Secret Phrase then you will need that as well.
You may reset your password on this page: Forgot Password
If you are using SINGLE PASSWORD, then all old emails and contacts will be deleted.