Encountered some difficulties on opening this blaster.
I bought 4 of these, although they don't ship to SoCal from Amazon. Got around that by buying it through their eBay store.
I've managed to crack the Eradicator open with a saw. A dremel or hot blade could work just as well for the threaded end of the barrel that is glued to the shell of the blaster.
Line up the cut as well as possible to the gap between both halves of the shell.
There is blue cover on the handle that hides two screws. There are notches that hold it in place. Use a screwdriver to pry that off.
Remove all the screws and there you go.