Hi all, first i want to thanks Mjollna's help on other topic.
Well, let's get started.
You'll need to download (if dont have it) HxD.
http://mh-nexus.de/en/downloads.php?product=HxD

Second you need is a .wmo file to edit, for example... this:

nexus_raid_floating_platform.wmo

Well, i want to do it more.. gray but i want to preserve the original WMO file so...
1. Extract the original .wmo file to deskopt or another dir.


Note: WMO files have _000.wmo, _001.wmo and more support files, extract them too, but dont change it with HxD.


2. We need know the texture files of the .wmo.
Know it it's easy, ModelWiever log write they when you load a WMO.


3. Now we're going to change de dir of tecture. Open your .wmo file with HxD.
You'll see this:

Imagine that I only want to change 1 texture and I have the custom .blp maked.
DUNGEONSTEXTURESNEXUSJLO_NEX_ENVMAP01.BLP will be DUNGEONSTEXTURESNEXUSJLO_NEX_ENVMAP07.BLPI only need to replace the name on the code:

BUT you cant use a longer or shorter name than "DUNGEONSTEXTURESNEXUSJLO_NEX_ENVMAP01.BLP"
Explain: If the dir of blizz texture have 44 caracters the dir of the custom dir must have 44 too.

4.Well, make a patch, put the new texture on the dir you've eddited (Mine "DUNGEONSTEXTURESNEXUS") and the .WMO on a custom dir (Mine "WorldWmoIago")

Remember, dont change the "_000.wmo" or similar files, only drop them on the same directory of .wmo custom.
Import the WMO with noggit or make a custom displayid by DBC and see the results:
[spoiler:21wmyu3l]

[/spoiler:21wmyu3l]

i cant see that really well on phone, but you've added a character right ? if that's the case, its a bad idea  you can replace existing characters in the texture name, but not use a longer/shorter name.

You've reason, i change the number without more characters and it works:
[spoiler:uzprd2xo]
[/spoiler:uzprd2xo]
(It's only a test, i'm better designer than this.. xD)

¡¡¡¡¡¡¡¡Thanks!!!!!!!!!

It doesnt work with m2, and ALOT of wmo's causes wowerror on 3.3.5a.