How do you find the phase of the DFT of a discrete signal?
Here is a hint that will help you:

The DFT is cyclical in time and in frequency. For the sequence given by

$$x(n) = [-1,2,-3,2,-1]$$

With x(0) = -3 would be solved using the standard DFT equation that starts at n=0 using

$$x(n) = [-3, 2, -1,-1, 2]$$

From that you can solve for the DFT and then determine easily for each result what it's phase is.