How to delete report and data source that I am not the owner of?

[LuKolo]

Long time ago I used a report as example, and since then the report and data source is showing on my dashboard. Ho can I delete them? The delete/remove option is greyed out at contextual menu.

https://datastudio.google.com/reporting/c9d3d6e2-6ac5-4864-bef2-784def1054db/page/VtvdB

https://datastudio.google.com/datasources/c49a41ad-7a1d-4d9a-912a-b94b30289704