Help

I'm Making a Jurassic Park Map and A problem thats made me stop completely in my tracks is a model problem. Another Person made some models in which he put in his map he gave me an unprotected version of it so i could get the models i exported and imported them into my map but every time i assign a model to a unit it shows up as a green cube and never shows up ingame what am i doing wrong? could sum1 show me a step by step tutorial of how to successfully assign models?

A) Do not mass emoticons.

B) I am sick and tired of answering this question every single day. Look in the Skinning / Textures forum, I explain quite clearly how to do it in a recent thread.