I will echo Andy's comments. After years (yes it has been that long I
have to admit sheepishly) of struggling with not being able to remove
the blade, I finally got a spanner wrench that spans the round collar
and is able to keep it from moving while I use the long handle nut
wrench to loosen the nut. You can buy the right spanner wrench from
McMasterCarr after measuring the diameter carefully and buying the next
bigger available size, in case you size does not exactly match. Here
is a link to the McMaster page
http://www.mcmaster.com/nav/enter.as...3&pagenum=2589
I got the A style wrench. The best $ 13.69 investment I made for my
saw. Solved the years of misery. Highly recommended.