In looking at the exploded views the screw that holds the rear drive shaft (7250/7251) coupling in place is labelled as "7057 M3/10". What size hex do I need to remove that? Seem like 1.5 is to small, and the 2.5 is to big. I guess it would be a 2mm?
In my case that is a 1.5mm wrench.
Nobody is born with experience
try another wrench, they vary in width. just a few thousandths is a big percentage of something ~.060 wide and you DONT want it to slip when you put the heat on it
There are lots of ways to do that. Most are wrong.
fyi.. a different 1.5mm worked perfect