Happened to me too, the pull cord didn't get pulled back in. But since the engine was running I took my knife and simply cut the cord off to avoid it being pulled into the propeller. And after an hours flight I returned home and performed an autopsy.
The outer end of the cord rewind spring had pulled straight. The end of that spring had been annealed too soft by the manufacturer originally, that part was very easy to bend by fingers alone. So, I snapped that part off and bent in a new hook, the spring steel appeared to be very soft and could easily take a bending without breaking.
Removing the starter is easy, just remove four bolts, and off it comes. Then to remove the pull start wheel, just remove the center bolt and carefully lift the cover off. The system only consists of few parts and it is easy to fix.