If you can find a scrap of scrap metal you can bend it in a "U" shape, drill a hole in it and use the steering wheel nut to pull it down.
If you have a second person to help you can push like hell and have have them put the snap clip down at the same time.
If you don't have help, do a google search for every cuss word you can find (and memorize them), find a socket that will slip over the shaft but tight enough to push the snap ring down, figure out a way to extend it with a bundled towel taped on the end.....
Take a few quick breaths to saturate the blood stream with oxygen... push like hell on the plate then bonk your pusher arrangement with your head. when that didn't work, try again until your fingers get tired. After a few more attempts when they are still tired go inside and drink a beer or three.
Then walk back outside and it'll go right on the first time without even getting tired. (sorta like removing the PS valve cover)