Have you tried sergbuto's retexturing guide?
http://web.telia.com/~u18216264/Retexturing_Guide.pdf
About .ace. I agree, it is a very good compressor. I am using also 7z.
@Mountbatten
Another option to process .ace files is IzArc archiver. You can get it here. Unfortunately, it does not support Linux which is my favorite OS.
But it is very good on WinDoz.
http://www.izarc.org/