Problems installing thief expansion mod

[Tyrakh25]

Alright, alright....

This is my first time using WeiDU, and I'm a wee bit confused. I've checked all the help files and everything but im still shtuck. I start the installation and it asks me if the language should be English or German. I hit 0 for English then it gives me errors about translations and the setup-.tp2 not being found. Ive tried to relocate the file to the folder where it said it was missing and about everything else I can think of, but I still get the same error message. I know this is problem is probably too vague for anyone here to help me with but I was jus tryin everything I could think of.

Thanks for any help.