Howto unlock wedge brake nut

[Plasa]

Hello guys.
Today I tried to do the brake maintenance of my M1078 A0 truck. The brake itself was quite easy to rebuild, but I was not able to loose the nut that fix the brake chamber, to be able to unscrew the chamber from the brake assembly.
How did you loose that nut, or can I try with a big wrench to unscrew chamber with the nut in one time?

Thank you for your help!
Christian

 

[NDT]

Hit the nut’s ear with a drift punch and hammer.

 

[Plasa]

Tried, but I already destory 1 ear...

 

[Suprman]

Heat a little with propane plumbers torch