Upstate ny is correct it is NOT reverse threaded. The removal tool you pull down towards the cab floor turning CCW

I bought a set of left handed drill bits for such occasions. I had a twisted off bolt in a blind hole when moving platform strippers in on the 920 head. Center punched the bolt and used left handed drill bit. Extractor went in and I turned it out by hand. 

Be sure to use anti seize on the new pump shaft when you install it.

Let us know how it turns out.