There's a small hole in the peg, it should have a spring in it, there's a small ball bearing that fits in front of the spring & between the SS plate. It'll fit the peg itself. Line it all up and carefully slip it in the bracket, line the holes up & push the pin in. Then there's a small washer & a cotter pin the holds it all together.
It can be a real PITA to get everything lined up & to go in right. Put a big towel down to catch everything when you don't get it the first try. Note: It'll only go in the correct way BUT it'll almost fit the wrong way...…..don't let it make you crazy...………….. be patient