How to install the actuator spring?

Hoover Dimension Model U5209-930. I bought a replacement wheel assembly for this unit. When I pulled the old assembly out, a spring shot out. It is called the cam actuator spring. It's V-shaped and has a hole on one side that looks like it should fit over a round plastic protusion that's about the same size on the wheel assembly. But I can't figure out how it could possibly go back into the vacuum. I've tried every angle and position there. Any help would be appreciated.