This requires that the advanced tools, Task Utilities, be unlocked for you by the Support team and that you have Org Admin access.
This advanced tool is a quick and simple way to transfer all incomplete tasks from one user to another. This functionality can also be used for transferring incomplete tasks of staff members who no longer work at your firm.
How to Transfer Tasks
1) Navigate to the Menu > Advanced > "Task Utilities."
2) Select the user whose tasks you want to be transferred.
3) Select the user who should receive these incomplete tasks.
4) Confirm the reassignment you are making by reading the summary below and click on the "Assign Tasks" button to finish the transferring of those tasks.