Custom Icons on the Taskbar?

Ive been trying to customize chrome, skype, etc icons that show when the application is active on the taskbar but nothing seems to work. I've tried changing the icon of the shortcut or pinning the shortcut to the taskbar.

I've also tried using registry hacker to change the icon files in the application but then whatever application i change the icon files to it just becomes unusable. I hope someone can help me with this. I can post screenshots of what im talking about as well

and how might i be able to do that? ive tried finding the icons that could be in the folders for chrome and changing them which did nothing. seriously confusing

the only icons i can change are shortcuts, i cant change the chrome application icon in the properties

So ive been experimenting since my last reply, granting myself all the permissions and found a way to change the application icon but it still didnt switch it when it is not combined with the label (see first image.) however if its shortened down without the label it ends up using the right icon? (see second image)

Cool thanks. its usually in a .dll file then? if so then i can dabble in a couple of different areas for different programs

the only things i want to change are battlenet, league of legends, skype and steam. everything else is fine and i dont really care about skype as it has different colours for each status and notifications on the icon