2 oz or so of C-4 agent should do the trick, but then you should already know that Blast!

Alternatively, about 6 wraps of det cord at the base ought to open it right up. The problem in both cases will be getting it closed again.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)