Managed to do the inside ring which was very fiddlely but thanks to the posters on here plus dandys pics all done in about and hour
I would Just like to add to the previous tips,
I unbolted the vac pipes and the injector pipes off the back of the pump to gain access to the block/engine side with my left hand which does help(too cold to take pics sorry) and use a piece of signs wire with a sharpened end formed to make a kind of hook to remove the o-ring...
Thanks Guys and Merry Christmas
P.s my other half's pruning mirror was very useful..





