I need to replace the left hand engine mount on my EF V8. Can this be done without removing the engine. Any help would be great

I dont have formal documentation, but should be doable.
Support Engine on side you are replacing. Engine Crane probably best to front of headers
Loosen top Nut, on Mount, and through-bolt (where Lower Mount bracket Bolts to Chassis)
Take up Weight on crane, lift slightly (engine will rotate - be careful) and should come out fairly easily.

If that doesnt do it, might pay to undo the two bolts on engine and manouvre the mount plate out of the way.

Have fun.

Good luck - you'll probably find the stud will spin in the mount, so it is a real pain to get the nut undone.