From the OS X desktop itself with its built-in search function called Finder, we can access all kinds of folders, files and other content on our disk having as an option the be able to delete such files to move them to the trash dragging them, selecting a group and pressing CMD + DEL or from the contextual menu to be able to choose to delete them with the option for it.
Anyway, although this feature should work within your session for all files, many times when we choose to delete one of them to send it to the trash, option is grayed out and does not allow to do so.
This setback occurs because your user you do not have permission to modify the file or folder in question, for this reason we will have to grant permissions for OS X to allow it to be moved. This is based on the POSIX permissions configuration that, having been modified, can prevent your account from having permissions to modify those files, it is also possible that there are access control lists behind or other complex configurations. To solve this problem, we will have to locate those problematic files and change their properties, which will open the terminal and enter the following commands, step by step:
sudo chmod -RN
After this, we will leave a space after 'RN' and we will drag with the mouse the file or folder in question so that the path looks like this:
sudo chmod-RN "File path"
Now press Enter and we will give the password when requested.
The next thing is to do the same thing again in the same way but changing the attribute 'RN' to 'R-666'.
This will remove any property attributed by access control lists to release the file or folder. It is also advisable to enter Disk Utilities and repair permissions once all of the above is done.
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