Carbs off it's not bad might be a bit tricky and involve some hands and knees time with them on the bike. The left carb gets the ball and spring. There are three small detents in a row on the choke rod. anyway put the spring in the hole and then the ball, a little grease on the ball may help hold it, it will sit just sticking into the bore for the choke rod. insert the choke rod, a little grease helps, with a light twist if necessary, keep track of which way the detents face. get the choke lifters on the rod as you insert it or try again.