Icons used by the executable files are actually embedded resources inside the program file itself. It is not easy nor is it completely safe for your system to modify these resources.

ICO Converter is a program found online that will take any image file and convert it into an icon. Take a PNG, GIF or JPG and convert into icon files. This program doesn't need to be downloaded ...

If Microsoft Word icon is blank or missing, & not showing correctly or properly on .DOC & .DOCX document files of Office, then see this fix.