Is it possible to force replace files on iMac?

Question

Is it possible to force replace an item that's in use? Because I'm trying to replace the dock image, but since it's always open it wont let me.

Answer 1

• Go to Macintosh HD » System » Library » CoreServices.
• Make a copy of the Dock.app so you can go back if you ever war to.
• Right-click on Dock.app and select “Show Package Contents”.
• Go to the contents folder, in the contents folder go to resources.
• Copy the new dock images there, it should ask for an admin user name and password.
• After the images are cooped in, go to the terminal and type ‘killall Dock’ and hit enter.
• The dock should relaunch with the new images.

Answer 2

Try this: in the terminal type: sudo mv then drag the replacement image into the terminal window and then the original image. You'll need an admin password.