You're gonna be looking at editing the source code. If you really don't wanna do that, or just want a quick and dirty solution to see how it looks, replace the images with 1x1 transparent gif's and watch them disappear.
If you search Google there are plenty of hacks out there. I remember once finding a hack for VB that changed the moderator and administrator link colors. Try searching for it. I am sure someone has all the coding and all the files that need to be edited. I would highly recommend just using new icons. The text will be very hard to deal with :imho:.