How do you actually go about it?
The stock DKFH sample for the kick isn't doing it, and I have a few that I grabbed off of the Sneap forums that I'd like to try out. When I go to pick a kit though, all I see is the default EZX's for options:
How can I yank the stock sample and use something else?
Use something other than Toontrack. I don't like that about SD2 either, you can't use external samples, only ones specifically from Toontrack. For using wav samples and such you've gotta use Drumagog or something like that.