Now that you know where it is, and how to get at it... Perhaps you can heat up, and bend some existing wrench into a task specific tool to make it easier the next time. I have dozens of task specific tools, and the time, and aggravation they save are well worth the sacrifice of one tool.
I don't know if this next bit applies... When putting anything back together I always sort of "hang" the part(s) on the bolts or studs. I never even finger tighten anything until all the fasteners are in place.
Scooter plastics are a world unto themselves. Like those "magic" bent nail puzzles. Once you know the secrets, you can do them w/ your eyes closed.