Change all file icons with same type [Yosemite]

Question

I have many excel files in my computer, and the icon of all of them are plain paper, like this:

I want all icons to be .numbers icon. Do anyone know how to do that ?

Answer 1

Here's what you could do :

• Open a Finder window and navigate to /Applications/
• Find the app whose file icon you want to change
• Right click it and select "Show Package Contents"
• Navigate to Contents/Resources/ and find the appropriate icon file. Replace it with your new icon file.
• Restart your computer to update the icon cache.

Or you can change the default app for a file type and set all files of that type to be associated with the default app if that's what your question says:

• Open a Finder window and locate the file type you want to change.
• Push Command+i or go to File > Get Info
• Under "Open With" select the app you like. You have just changed the default app for that individual file.
• To change the default for all files of that type, push the "Change All" button and then "Continue"

This will make all your excel files to open with numbers while the previous one will just change the icon

Answer 2

To change the file icon on all you files icons with the same extension:

• open Get Info panel file 1, that you want to change
• open Get Info panel file 2, that you want to change to
• drag and drop icon from panel file 1 to panel file 2
• click Change All...
• with Finder open "Show View Options" or command + J
• drag Icon size as you wish. This force icons cache rebuild