>>389745667
>How hard is it to rip a model from a game
Pretty sure that's completely dependent on the game and the engine the game is running on.
>and plop it into vrchat?
Should be pretty simple but you'll most likely need some kind of blender experience since the bone armature from the game might need to be edited to be more in line with VRChat/the unity default armature.

Deviantart also has a lot of game rips for download that are already converted to something like .xps which makes things way easier, and no ripping required. I'd recommend searching there first to see if what you're trying to rip is already there.