We re-factor as $(x+1)(x-3)(x+2)(x-4)\left(x^{2}-2 x-1\right)+24$, or $\left(x^{2}-2 x-3\right)\left(x^{2}-2 x-8\right)\left(x^{2}-2 x-1\right)+24$, and this becomes $(y-4)(y-9)(y-2)+24$ where $y=(x-1)^{2}$. Now, $(y-4)(y-9)(y-2)+24=(y-8)(y-6)(y-1)$, so $y$ is 1, 6, or 8. Thus the roots of the original polynomial are $\mathbf{0}, \mathbf{2}, \mathbf{1} \pm \sqrt{6}, 1 \pm 2 \sqrt{2}$.