Try the proper steps:
Fix permissions on Trash folder
Select your Home folder and press COMMAND-I to open the Get Info window. Be sure you have "read & write" privileges in the Sharing & Permissions panel. Check under "General" panel to be sure it isn't locked. If that is correct, launch the Terminal on the Utilities folder, and at the prompt copy and paste this command:
If you get a message that the folder already exists, copy & paste this command:
sudo chown $UID ~/ .Trash
Press RETURN. Enter your admin password (it will be invisible) Press RETURN.
Then copy and paste this command:
chmod u+rwx ~/.Trash
Log out and back in, or restart.
If the backup folder you have in the Trash contains files from a Time Machine backup then plan on hours or days to delete the folder if there are no problems. Although the .backupdb folder is empty there are other folders inside that may not be empty.