1. Right-click TextEdit in the Applications map
  2. Click “Show Package Contents
  3. Go to the “Contents” folder
  4. Open “Info.plist” (with an editor)
  5. Scroll all the way down
  6. Find
  7. </dict>
    </plist>
  8. Place this code right above it:
  9. <key>UTExportedTypeDeclarations</key>
    	  <array>
    	    <dict>
    	      <key>UTTypeConformsTo</key>
    	      <array>
    	        <string>public.text</string>
    	        <string>public.plain-text</string>
    	      </array>
    	      <key>UTTypeDescription</key>
    	      <string>NFO information file</string>
    	      <key>UTTypeIdentifier</key>
    	      <string>com.macromates.textmate</string>
    	      <key>UTTypeTagSpecification</key>
    	      <dict>
    	        <key>com.apple.ostype</key>
    	        <string>TEXT</string>
    	        <key>public.filename-extension</key>
    	        <array>
    	          <string>nfo</string>
    	        </array>
    	      </dict>
    	    </dict>
    	  </array>
  10. Close and save the file
  11. Open Terminal (in the Applications\Utilities folder)
  12. Enter the following, and press enter
  13. touch /Applications/TextEdit.app/
  14. Close Terminal
  15. Done