I think garages tend to crack off the nut with an impact driver with the timing chain still on and then lock it before taking it all off.Hi mate. Tks for your reply.
Why I asked is the instructions for the timing tools mentioned that it should not be used as a support for unlocking bolts or nuts. I do not have a Haynes manual but I downloaded a video of someone changing a timing chain on a Vauxhall Agila but they did not mention about that crankshaft pulley. That pulley sure is very tightly screwed.