How can the owner of an ad hoc report be changed? A report can be shared, but others cannot edit it.
SAP BizX Ad Hoc Reports
There are two ways to make another user the owner of at least a copy of an ad hoc report. Unfortunately neither can be done for multiple reports at once.
1. Share a report with the recipient. The recipient clicks it and selects "Save As" to save a copy with "self" as the owner of the copy.
2. Export the report definition and provide the recipient with the file produced. The recipient uses "Upload Report" on the file, and saves the report with "self" as the owner.
KBA , LOD-SF-ANA-ADH , Adhoc Reports & Report Builder , How To