Reassign notes & activities for a contact person that leaves the organization

Reassign notes & activities for a contact person that leaves the organization

What are you doing in such cases?

I have created notes for contact persons about phone calls and meetings. 
And now this guy is leaving the organization. The notes are part of his old company and I want these notes to be reassigned to his successor.

Is there a way in Zoho CRM to do this?
Or what are you doing to prevent this from happening?

Thanks in advance !