Ruari
I did my on my Disco 2 and it was a pure pig to get the starter out. Found it dead easy once I broke my fingers, shaved bits off them and took loads of drink.
Seriously though, I used a good selection of good quality 3/8 drive sockets, extensions and swivel joints. From recollection it would have been almost impossible to get the soleniod to split to be able to change the plunger.
Once on the bench the job was simple. The hardest nut to get was the top one. As they say "many TD5 starters don't have a top nut fittedar" - wonder why
Duncan