Go to Search bar and type Disk Cleanup. Select the C: drive to clean up from the drop-down menu and click OK. After the scanning is complete, select the files you want to delete.

Also, if you browse for your own icons, you can select any EXE, DLL, or ICO file. 8] Finally, click the ‘ Apply’ button and then hit on the ‘ OK’ button to save your settings.

For PDF files if you want the generic PDF icon and not a copy of the file itself, you'll first need to do a File->Get Info, select the icon in the Get Info window, press Command-C on your keyboard ...

Next, right-click (or Ctrl-click) the file or folder whose icon you want to change and select Get Info from the contextual menu. Click the icon in the top left of the Info panel to select it.

This function can be turned on and off in Finder -> View -> Show View Options by checking the box next to Show Preview Icon, but in some cases it may not work even if you have the setting enabled ...

Step 2: Whether a file or a folder, you’ll open the properties for it to access its icon. Select the file or folder and pick File > Get Info from the menu bar or right-click and choose Get Info.