Had a loose prop and when trying to take off it tipped and broke one prop and another is now stuck on. it flew well before i discovered it. It does not push down when trying to remove, like it is twisted too far. Any idea on how to get off safely? Also where to get black props like came with from Best Buy? Also will the white ones fit?

Hold the silver drum of the motor and twist prop back then push down and twist to unlock.  Once off don't use this prop again as the scuring post could be cracked.  White props fit the same as the black ones.