Converting other games weapons to GMod

I was wondering how someone would go about converting weapons from other games (in my case PUBG) to GMod. I’ve seen people do this before with BO2 and csgo weapons in the game but do they model the stuff themselves or is there an easier way to do this for someone whos not really into modeling.

Wasn’t sure if this goes in modelling or Developer Discussion btw.

I think they ripped the model and animation,then they code it entirely from scratch.
If they can’t rip the animation,they also have to animate it

To add to Zufeng’s reply, you can rip models and animations from a different game but not a weapon’s behavior. GLua uses a pretty standard format to create weapons (SWEPS), a good guide can be found here.

Where you come across SWEP.WorldModel and SWEP.ViewModel is where you would insert the ripped model for example.