you are doing the right thing you may need a couple of try's to get it in the right position ,the square in the middle of the finger is a friction fit this has come loose.
Allow the clock to get to a strike position, stop the clock, remove the minute finger and move the square a little bit refit has the finger moved closer to the strike position ? If yes remove finger turn square some more keep trying till finger is in the right position when happy need to apply a small blob of solder to the back of the minute finger and center boss
wirecutterman
June 2011