Finding Real and Complex Roots of a Polynomial Equation

Hi there,

I have to answer to following question, and am having issues:

Given that $\displaystyle 2-i$ is a root of the polynomial equation

$\displaystyle z^6-5z^5+8z^4-2z^3-3z^2+3z-10=0$,

find all other roots.

I can see that $\displaystyle i$ is a root, and that because of conjugate pairs, $\displaystyle -2-i$ must be, and I understand that there must be 6 roots due to the degree of the polynomial, but I don't know how to find the other 3. Any advice or pointers would be hugely appreciated!

Thanks in advance!