I will assume you want something vaguely scientifically plausible. (I will also assume when you said "small black hole" you really meant one that is small enough to be contained on the surface of a planet and that the 4' size was not what you really meant.)
To start with, you can't destroy black holes. You can -- with difficulty -- move them. You can feed them and make them more massive. You can charge them and change their spin. But that's about it. So pretty much all you can do is try to get it up out of the planet, and that requires as much thrust as it would to launch the same mass of ordinary material into orbit and a way to apply that thrust to the BH.
(It's true that BHs probably evaporate due to Hawking radiation (though it's never been observed), but if HR is real, evaporation takes a very long time.)
The only way moving the BH might be doable (which wouldn't necessarily destroy the planet as a side-effect) involves charging the BH and then using electromagnetic fields to accelerate it. Pretty hard to do!
That brings up the question of the BH's mass. If it was temporarily contained, then it must have had a large charge and been supported by EM fields. It's mass is its mass, and if it was a small BH -- say the same mass as a mountain -- the containment facility would need to be able to support that mass concentrated into a really, really tiny object. The Schwarzschild radius of a BH of 100,000 tons (which would be very difficult to support with any imaginable technology) would be about 10-19 meters which is roughly 1 millionth the diameter of a proton.
Something that small would find it very difficult to swallow anything, so while it would orbit inside the planet, it would grow only very, very slowly. It would probably come to a halt (due to dynamical friction) at the planet's core and just sit there growing very, very, very slowly. It would probably have no effect whatsoever on a thousand year timescale.
The bigger the BH, the more of an impact it would have, but the less likely it would be that it could ever have been contained at the planet's surface.