I need some help about putting a model into TF2

Hi everyone,
I am a host of a TF2 VS Saxton Hale Mode server.
My friend and me are going to add a new character into the mode.
This is the model that we wanna use.

There are two files called sak.mdl and sak_animations.mdl
Can somebody help me to combine those files into one file?
because I only put the sak.mdl into my server,
the character will got no animation.
Plz help me~