In order to transfer ownership of a schedule you must be reporting administrator (member of Reporter_Reporting_Admins security group).
Transferring ownership of a schedule also transfers ownership of all reports belonging to that schedule. The credentials for the transferred schedules must be re-configured by the new owner.
To transfer ownership of schedules:
1- As a Reporting Administrator, go to the Schedule tab of the Report Manager.
2- Click Ownership at the top of the list of schedules.
3- Select the existing owner of the schedules to be transferred.
4- Select the user to whom the schedules will be transferred.
5- Select the schedules to be transferred.
6- Click OK.
7- Click Yes to confirm the transfer.
NOTE: A red warning symbol at the top of the transferred schedules indicates that the credentials of the those transferred schedules must be re-configured. The new report owner must click the pencil icon beside the warning symbol and select an account with the appropriate credentials.