Different Character Model?

I made a new character model with elbows and knees, and i want to give players that character model. Changing the character value in a player doesn't work and it bring their old character back. Is there a way for me to give players control over a certain model (a model with humanoid and animate script in it)?

http://www.roblox.com/BetterCharModel-item?id=295361280

That's the model if it's useful. Also i made an idle animation using this, put it into the animate script but it gives the "Asset not trusted for this place" error, even though i made the animation. Could it be beacuse of that i imported the normal idle animation, made changes and uploaded it?