If you have two similar contacts and would like to migrate all the data into one record, you can follow these steps:
Navigate to the duplicate contact you do not wish to keep (or the one with the least amount of emails and notes on the timeline).
For any emails on that timeline, you can open the email by clicking on it. From there you can add the email to right timeline, by clicking 'Add to timeline' in the menu on the right, and then remove it from the other timeline by clicking 'x' next to the one you want to remove.
For notes, you can copy and paste the details in the notes or simply open the Note options menu and select, "move".
Copy and paste any detailed information to the contact you are wanting to keep.
If you have any work that needs to be transferred, you can go to the work item menu ("...") and select Change client.
Once you have gone through and moved all details, notes and emails to the other duplicate contacts, you can delete the contact you no longer need.
If there is too much data to move over or you want to delete multiple duplicates in bulk, our support team is happy to help you. Contact us in Help & Feedback off the main menu, and select Still can't find what you need. Let us know the names of your two contacts and which one you'd like to keep, and we'll take care of this for you.