Change Task Owner (Bulk)

Change Task Owner (Bulk)

Hi,

A user has left the company and we have approx. 1000 tasks spread across 100's of projects.
How can we bulk reassign everything that is open for the inactive user to a valid active user?

Is there a workflow/rule like 'where task owner is xxx and status is open, change task owner to zzz' that we could setup?

Thanks

Rob

Thanks.