Turn the rifle upside down,place that pin in the hole in the frame(it's under the grip) and that spring goes in the hole in the grip and the hole over top that little pin.If you have any more trouble let me know.The safety is swinging free because the spring and pin hold pressure on it.
Put the safety body back in, and hold it in the Fire position. Then take the little gold detent and put it back into the little hole it came out of. You will see a hole in the pistol grip - put the spring back in there. Then put the grip back on, aligning the detent and the spring. Screw the grip screw back in (make sure you have the silver washer on it), make sure your safety works, and you're good.