\[4m^{3} - 4(m + 2)\left( 4 - 2m + m^{2} \right) =\]
\[= 4m^{3} - 4\left( m^{3} + 8 \right) =\]
\[= 4m^{3} - 4m^{3} - 8 = - 8.\]