What have you tried so far?. These problems are just routine knowing the corresponding theory.
I'll show you how to do one, then you try to do the other...
Note that this complex number is in the third quadrant. The angle in the first quadrant is .
So the angle in the third quadrant, .
There are always three cube roots, and they are of the same magnitude and evenly spaced about a circle. So they differ by an angle of .
So the other solutions are
But since , we rewrite this as