efion did what I wanted to do.

Actually this will cause a .png in your mass storage, would be nice if you overwrite the original icon.

First of all, you need to know the location, I assume in

/usr/share/icons/hicolor/80x80/apps

Name: cutewiki80.png (I don't have this software installed, you need to check on the name, I'll use this name for the rest of the steps.)

Rename the new icon to cutewiki80.png, put in mass storage.

Open terminal, devel-su, password

cp /home/user/MyDocs/cutewiki80.png /usr/share/icons/hicolor/80x80/apps

Restart your device, then you will have the new icon. And you can delete the one in your mass storage in case it messes up your gallery.

If you have any questions please tell.