Yeah, it wasn't a smooth operation when I did mine, if you have a small pry bar I'm sure that could help. A little forceful persuasion probably wont hurt either, it's been a couple months since I went through this process so I'm a bit hazy, but I believe I was able to slip the bushing onto the bar, then push/pry it into the right position.
Thinking about it with hindsight and those pictures, I would imagine if the bushing was put on the bar with the flat side forward and the split facing down (seeing that the sides are the thinnest part), you could likely get it into place by then rotating the bushing until it the flat side just falls into the mounting surface on the frame that it connects to. Maybe I'm overthinking it, maybe we both are. Like i said, the bushing can take a bit of persuasion and be fine, just not sharp objects and I would probably use a rubber/wooden/rawhide mallet before a metal hammer on it. If you are just using hands for persuasion, definitely no need to worry, you aren't going to ruin that bushing with your bare hands on accident.