We can use distribution property to multiply the polynomial by the monomial.
$$ \begin{aligned} \color{blue}{-2w^2} \cdot \left( w^2-4w-2 \right) &= \color{blue}{-2w^2} \cdot w^2 + \color{blue}{-2w^2} \cdot \left( -4w\right) + \color{blue}{-2w^2} \cdot \left( -2\right) = \\ &= -2w^4+8w^3+4w^2 \end{aligned} $$