Looking To Edit Textures In GW2

I'm not sure if this is the program to do this or not, but I'm looking for a way to replace one texture with another in Guild Wars 2.
Specifically, I'm trying to replace the chest mounds texture in the Silverwastes map to something more noticeable so that chest farming is much easier.
If anyone has any idea how to do this, please let me know!

wiki.guildwars.com/wiki/Player-made_Modifications/TexMod

texmod will work for GW2 as well.