Hi guys, need a little help here: I deleted some older time machine backups (I shouldn't have, now I know), and they are in the trash. I'm trying to delete the files but I get a message saying "The operation can’t be completed because the item “Macintosh HD” is in use." Macintosh HD is my internal drive. This is a 2013 iMac and it's running on Sierra. How do I delete the files in the trash?