Hi Marvin,
One pointer is just other PRs converting old style functions to new: https://github.com/pytorch/pytorch/pull/1507 58
https://github.com/pytorch/pytorch/pull/1426 28
Another is this detailed comment:

  
      github.com/pytorch/pytorch
  
  
    
  
    
  

  
    
      Autograd refactor
    

    
      pytorch:master ← pytorch:autograd
    

    
      
        opened 
        
          
        
        Mar 16, 2017
      
      

      
        
          
          apaszke
        
      

      
        
          +2723
          -1585
        
      
    

  


  
  
    
    
  
  


Primarily, you need to define the backward of ConvNdBackward as ConvNd, i think.