Bring up the Trash Manager (Site/Trash Manager) and you will see a list of items in the trash.  There is a drop down on the left side to select Menu Items or Content Items.  Click the checkboxes to either Restore or Delete the item(s).

Once an item is deleted from the Trash Manager it is unrecoverable.

It is always a good idea to clear out the trash manager as the items take up space on your account.