OK, what's the idea here: You have a few files, .sur and .cmp, they are packages of files (sort of like zip), they contain various files inside, one (or more) is the texture (skin), you need to extract that file (I think it's in dds format). take that out, edit, put it back.
That would be the idea, I'll have to take a look to say any details as to how/which file and so on but I'm sure there's an explanation in the skinning tutorials.
If the stars should appear one night in a thousand years, how would men believe and adore and preserve for many generations the remembrance of the city of God? - from 'Nightfall' by I. Asimov The Outcasts consider Siniestre Nube a sacred place for several reasons. Early explorers discovered a jumphole within the depths of the cloud that leads to a strange world of ringed stars and strange craft. All ships in the burrial ground are placed facing that hole to honor the Alien Spirits. - An Outcast rumor