On the panel of each individual post (object, material) there is a cross icon (on the right) - click on this cross. The system will ask for confirmation of this action (yes / no). If you click "Yes", the post will be deleted immediately. However, before deleting the material, pay attention to its popularity, the number of participants in the discussion, the number of comments. Probably, this material is very popular, relevant to society, or to somebody for some reason. Do not rush please.