You'll have to completely replace the fitting with another one. See here for an example
. I might recommend using some sort of quick-connect fitting. Ask at your local plumbing or hardware store about where those are. I'd also get some epoxy putty, assuming it'll stick to the fitting you bough. From there I'd saw off the old fitting on the blaster end, clean it up, sand it, and then attach the new fitting with epoxy putty. Might not be pretty, but will do the trick.