Just managed to remove the starter motor from my defender 110, tried following the instructions above only discovered after a lot of mucking about that the top nut is a 17mm not 15mm as stated above for a discovery. Also I managed to get the socket and extender onto the nut from above then dived under to put the ratchet on and undo it. As my nut was a nyloc one needed the ratchet to undo all the way.