How to extract textures and models from custom maps?

[Nuclear Era]

Hello there, I'm new to the forums and new to the map making scene!

I was curious on how to potentially extract textures from a model within a custom map (ex. dr_playstation's bud card textures) and even incorporate those custom models (ex. the PS1 model) into my own map?

I've been having trouble looking for a similar thread pertaining to this, so I thought I would post one here regarding my situation.

Anyways if anyone can help, please let me know!