Greetings. Before I tell you about what I need help with, first I'd like to tell you a little bit what I'm doing. As you all probably know, Windows XP comes with a classic skin, but most of the icons are still the XP icons, sorta defeating the purpose of having a "classic" skin.. So I've started "Project Make Windows XP Look Like Windows 98." I'm going through and changing as many icons as I can to resemble those from the 98 era. Observe:

So right now, I've successfully changed the desktop and quick launch icons to look like those from Windows 98. But now I'm just stumped.

The start button icon and the start menu icons. I can't simply right click, go to properties and change the icon. This is where I need your help. Is there a way I can change these icons, or is it just not doable?
Thank you in advance.