I'm in the north east mate. Would there be any chance of posting it too me or is it not worth the risk. I am getting a garage to do it but they do not have the tool and they would rather do it using the tool if they or myself can get one.Yes, the pulley has to come off to replace the seal. The pulley bolt can be really tight!
There is a 50mm locking tool available to hold the pulley/engine from turning while the bolt is undone, but even this didn't work for me... I had to run a breaker bar from the socket to the floor and then operate the starter to get the bolt undone (mine is a diesel and I had the injectors out, fortunately).
If you're anywhere near Ludlow I can lend you my Laser locking tool and a 6-point 19mm socket.