I am attempting to repair a shattered housing mandrel on my Husqvarna riding mower. I have it largely disassembled however I am facing a common problem: a stuck nut on a piece that is moving. The only leverage I can get is with the tool on the nut and the blade below. I have done some reading and seen suggestions on heating the nut but I do not have an acetylene torch handy so I'm looking for good advise. I am familiar with some of the more obvious techniques; such as whats proposed here: [How to loosen a nut when bolt and nut move together?](https://diy.stackexchange.com/questions/7122/how-to-loosen-a-nut-when-bolt-and-nut-move-together)

Any advise?

![enter image description here](https://i.stack.imgur.com/D5I9R.jpg)