There is no longer a "delete" option for learners or libraries.
In order to archive a learner or library, simply click on the name of the learner or library, then click on the three dots in the right hand corner. This will display an archive option.
Type in the name of the learner or library and select "Archive". When you archive something, it will go into your "Archived Items" section.
If you ever archive something by mistake or want to restore an archived item, you can easily do so by clicking on "Archived Items" and pushing the "restore" button under the learner or library of interest.
Please note that you will need to reassign any and all team members who were previously connected to the learner or library prior to the archive. All team members fall off after an item is archived. If you do not have permissions to edit teams or libraries, you will need the assistance of someone who does have those permissions.