Relaying materials to a model

I’ve never really messed with modeling because it seems too annoying to get into, but say I have the model and material files for a certain swep, what’s the best way to go in and relay the model to those materials?

Is there a certain program or some such? Any direction is appreciated.
(I tried to look this up but it just kept coming up with things that weren’t relevant)

relay?

Ignorant use of a word, apologies, just trying to set it so a model uses certain materials.

[editline]2nd August 2015[/editline]

?

I meant outside of lua, like in the actual .mdl and so on.

I am doing it with lua, I just wanted to know if there was some way that wouldn’t require a lua code.

not without recompiling the model.