I see from your picture you have removed the center nut, this is not a good idea as if the flange comes off the shaft you will lose your timing, the pump should be locked with the locking bolt before this nut is removed.
A good idea for the future possible repairs is to get yourself a good quality set of 6 point sockets, mostly I think that the 12 pointers are not "grippy" enough to break the under-head friction of those non standard bolt heads, (M8 standard is 13mmAF), why they chose to use 10mmAF heads for M8 beats me.