My question is why are you unable to delete the files, even if they are locked, MacOS should warn you if you attempt to drag them to the trash and/or you might be asked for your admin password.Where are the files located
ie are they in a hidden or system folder? Are the files themselves hidden (the first character of the filename is ".")? Have you done a Get Info on them to see if you have read & write access t0 them? Even then in most cases you should be able to delete them without doing anything extraordinary. By any chance was yahoo installed via an installer and is it possible there is an uninstaller in the installer app or available for download?
Deleting the file(s) using Terminal is not difficult, but mistakes made in Terminal have the potential of doing severe damage.
Therefore it must be done with great caution so, unless you really know what you are doing, read and follow these instructions with great care and do not improvise or take shortcuts.
- Launch Terminal
- Navigate to one of the files in Finder then
- at the Terminal prompt copy and paste the following being sure it is followed by a single space
- drag the file from Finder and drop it on the Terminal window which will place the fully qualified unix pathname in the command.
- press Return
- Enter your administrative password (Note you will not see anything happening on the screen) and press return
- Terminal will prompt "remove" followed by the fully qualified pathname
- Type y followed by Return
- Return to step 2 and repeat for each of the files.
NOTE: Terminal (Unix) commands are case sensitive so -i must be a lower case letter i and it can be very difficult convincing MacOS not to "correct" and capitalize it to I. I had to disable
Capitalize words automatically in System Preferences > Keyboard > Text to write this post.