Open the pork roast and put it into your Instant Pot. Pour the hard cider on top, and close and seal the lid. Set the program to "Meat" mode, and the timer for 60 minutes.
Let the pot release the pressure naturally. This will also hold over very well on low slow cooker mode for a number of hours.
Open the pot carefully after the pressure has released. If you are in a hurry, let it sit for 20 minutes before using the pressure release valve. Shred the pork with two forks, and dump in the salsa verde, salt, pepper, and chile margarita seasoning. The roast should be fall-apart-tender at this point. If it isn't, you need to re-seal the pot and cook an additional 20 minutes under pressure.
Turn the pot onto "Saute", and adjust down to low. Let the meat cook for 15 minutes, or until This is going to simmer down the excess liquid. How much time this needs will vary based on how much liquid was released during the cooking process.