Can't get blade of riding mower

I am having the hardest time trying to get blade off. I have a 30" craftsman rear engine rider. I have always used a 7/8 socket and gotten it off. This time, it just won't loosen up. I am using a pipe as extension to the socket to get more leverage. I think the socket is actually slipping and the screw will nut will not catch and turn. I have sprayed dw-40 and that didn't help.

My next idea was to maybe take nut off at top of unit (above the wheel that holds pulley) as I think this goes all the way down to the blade. Hoping maybe blade would then drop down but hesitant to do this.

Any ideas? Thanks.

 

They can be stubborn. Your best bet is probably to find someone with an impact gun to zip it off for you.