Yeah - it looks like a permissions problem.
You should be able to delete the files as Root.
To enable Root, use Netinfo Manager in the
Applications/Utilities folder.
With Netinfo Manager open, click on Security
and Authenticate, type in your admin password,
and then click on Enable Root User.
Go to System Preferences and open the Accounts preference
pane and check Login Options - "Display login window as"
should be set to show name and password.
Log out and log back in as Root:
username= Root
password= the password you set for Root
Be VERY careful to type the commands exactly
while logged in as Root, and be sure to log out
and log back in to the administrator account
and disable the Root account after you finish
deleting the files.