The parallel component is obtained by the scalar product of $q$ with the dot product of $p$ and $q$, after normalization of $q$.
Hence $$\left(p\cdot\frac{q}{\|q\|}\right)\frac{q}{\|q\|}=\frac{p\cdot q}{\|q\|^2}q$$ i.e.
$$\frac{(3,-2,-1)\cdot(2,-2,3)}{2^2+(-2)^2+3^2}(2,-2,3)=\frac{7}{17}(2,-2,3).$$
The perpendicular component is the difference
$$(3,-2,-1)-\frac{7}{17}(2,-2,3).$$
If you multiply that by $q$, you get $7-7$.