Emptying the trash on your Mac is usually a fairly straightforward affair, but when the trash can't be emptied through the conventional methods, you may have to take more drastic measures. Repairing file permissions and using a brute-force method through the Terminal application will help you get stubborn files out of the trash and into the ether.
Click and drag the file, document, or folder you want to delete to the trash can sitting on the Dock on the right side of your screen. Alternatively, navigate to the item you want to delete and right-click on it to highlight it. Select "Move to Trash" from the contextual menu that opens up. Once the file is in the trash, Click any empty space on the desktop, then click "Finder" at the top left of your screen and select "Empty Trash" from the pull-down window. Click on the trash can to verify it has been emptied. If files are still there, move to the next step.
Move the item or items you want to delete to the trash using either of the above methods. Click on the Finder at the top left of your screen and hold the "Option" key on your keyboard while you select "Empty Trash." Click on the trash can to verify it has been emptied. If files are still there, move to the next step.
Quit all applications if you receive an error message saying the file can't be placed in the trash because it is open. Place the item in the trash through the conventional methods. Empty the trash by selecting "Empty Trash" from the Finder menu. If files are still there, move to the next step.
Repair file permissions. Open the Disk Utility application that resides in the Utilities folder in your Applications folder. Select your system hard drive in the window on the left side of the Disk Utility window. Click "Repair Disk Permissions" at the bottom of the Disk Utility window and wait until you receive a message that says the permissions have been repaired. If files are still there, move to the next step.
Click "Finder | Applications | Utilities | Terminal" to open the Terminal. Type the command "rm -rf ~/.Trash/*" without quote marks into the Terminal window. Press "Return." Click on the trash can to verify it has been emptied.
Be very careful when using commands in the Terminal. Using the incorrect commands can result in major changes to or complete deletion of critical files.