This is something I have been working on for some time now. S2-PIP (Source 2 Pony import Project). As it’s project name says, I am porting a pony (actually a changeling but the process would be the same for a pony) from Source 1 to Source 2. Why would I do this? I want my OC in VR… And I want a pony NPC but, that’s faaar into the future.
 
Track my progress here:  
https://trello.com/b/yXVJ2scI/source-2-pony-import-project
 
I will try to keep it updated the best I can. After figuring most things out, I plan to make a step-by-step tutorial on how to do it all. Making sure I cover every step I can so others can import their Source 1 models to Source 2 if they want to.