I just tried to edit the sprite (the HUD is called a Sprite, not a Skin) but I had to learn that it isn't done with just a pixel...
The Problem is that the Minimap is one layer above your interface, so if i change the interface/HUD the Minimap will be drawn above it and the beautifull blue dot i painted on the interface is unseen because he is beneath the Minimap...
So my Solution: This is something that can't be done without coding... Hope that Flayra codes it or learn the maps good enough not to need a minimap.... I hope first thing will happen, but I'm sure it's not top-priority for him...
Sorry, I really wanted to help, but it's out of my skills