Looking for some advice here .. I reinstalled the speed sensor in my 2015 Fit, manual transmission, and it sheared off. I forgot the shim washer between the sensor and the transmission housing, so the end of the sensor made contact with some part of the output shaft. The debris now circulating in there includes a magnet, metal cap, plastic, and wire. I'll have access to a boroscope starting Monday, so I may be able to see how bad it is.

Assuming that I won't be able to fish out any debris, do I need to open the transmission housing to fix this mess? Is that even possible without dropping the transmission?