Paul: Welcome to the group. You will not find a group of owners who are more proud, devoted and selfless than this Jag owners group.
I recently had ocasion to turn the crankshaft by hand. I tried numerous tools, including a rubber wench, to grasp the socket, but only one method worked easily. And that was to insert the appropriate size socket, as stated by others, and turn it using…(at this point I advise purists to avert their eyes), an appropriate size pipe wrench. I think I used a 6” wrench. The problem is, as others have already said, there is very little space at this location. The pipe wrench worked best because I could easily grasp the socket, turn the few degrees that other engine parts would permit, and then easily grasp the socket again.
Appprepoe of nothing, I caution you NOT the turn the crankshaft backwards.
I did not try it but believe working from below would work as well, with more conventional auto repair tools.