I still don't think I'm understanding you. Are you asking how to edit the ServUO.exe? If so, you just edit the files contained within the "server" folder provided on the Git page (using Notepad++, Visual Studio, SharpeDevelop, etc), and simply recompile it into a new ServUO.exe.
If that also isn't what you're asking, then you may have rephrase the question or use a different translation software.
Then how do you explain this to me: I downloaded the client from the official site (uo.com) and it went through quietly on the pirate server RunUO? (http://runuo.theabyss.ru/). I do not think it's about the client!
Fingers jumped in before I had time to reply (Sorry work was intense yesterday). Yes, you can use the link Fingers posted to decrypt the client without need of using Razor or UOSteam. You just have to modify your login.cfg.