Thanks for the input, Mark. I had actually thought of both of those points.
I plan to put two bricks through my gun tomorrow and was going to wait until after that to replace the extractor in any case. The guy I am shooting with tomorrow has a lot of experience with guns, and is a mechanic to boot and I was going to have him help me.
But after I looked at the instruction link that yzguy kindly provided, I don't think I would have any trouble on my own. So I will probably leave the stock one in until I have problems (if ever). I have it under the pad in my case if I ever need it.