I took out the pivot bolt to give me more room. That allowed me to get a Dremel in there and sand down the metal knobs a hair. Which was enough to work it wiggle the harness free and put the new one in. It was all for nothing though as it was not my issue.
I had the same exact problem. Got to my trail and tried to turn on the bike and nothing. Took everything apart and found a loose pin just like you. I pushed it back in and then epoxy it in place. The bike will turn on for 2 mins before shutting back down. Then I noticed while I was testing...
I have to do the same thing. Did you ever find out how to get the harness out? I was planning on cutting the barbs out, but there has to be a better way. What issue was your Rise having that made you want to replace the harness?