E30 Zone

i was changing my speedo sensor which is located on the outside of the diff but i managed to break a piece of it and it has fallen into the diff,
would i need to replace the diff ?
open the diff and clean it out?
could i leave it without any major damage caused?

if it was me i would drain it out and see if it come out with the oil if not i would take it out but that just me, someone else might know a better way or have diffrent advice for you

Not difficult to take the rear cover off.

thanks guys i will take of the front cover