You usually have to drive the Sear pin out and let the Sears fall free to allow the stock & frame to be separated.
If the Trigger Plate is on tight and it generally is, use a slender punch and drop it down the empty Top Tang Screw hole. Let it bottom out in the Trigger plate boss. Then tap on the punch and it'll loosen and lift the Trigger Plate free of the Frame to help remove it.
Don't try and pry it free,
Once the Trigger Plate is off,,the Bbl Trip coil spring is free to be removed, just pull it out of the hole in the underside of the frame so it doesn't get lost.
The Bbl Trip itself, the U shaped part can then be pushed out from the action flat and out the bottom of the frame.
Good to do that as well to avoid it falling free and getting lost.