Is it possible to edit 3D models in 3rd party (not my own) Unity games? [My Time at Portia]

Thanks for that, I had a look and tried following it through but it seems to only show you how to edit lines of code like changing attack damage etc.

I tried to give it a go anyway because I thought I might be able to change model IDs (like I mentioned earlier) but “Unity Assets Explorer” the guide told me to use doesn’t respond when I try and load the files I’m supposed to. I left it for like half an hour thinking it was maybe just slowly loading everything but still just always not responding