How to separate HCl and NaOH from salt and water solution?
Unless time travel is an option, you could 


Electrolyze the $\ce{NaCl}$ solution to obtain a solution of $\ce{NaOH}$, and $\ce{H2}$ and $\ce{Cl2}$ as gases. 
Collect the gases and photolyze them. The dissociation energy of $\ce{Cl2}$ is $243\, \mathrm{kJ \cdot mol^{-1}}$, irradiation  at $\lambda$ &lt; 490 nm will cleave $\ce{Cl2}$ to chlorine radicals and initiate the chain reaction to yield $\ce{HCl}$ gas.


$$\ce{Cl2 -&gt;[h\nu] 2 Cl*}$$

$$\ce{Cl* +\  H2 -&gt; HCl + H*}$$
$$\ce{H* +\  Cl2 -&gt; HCl + Cl*}$$


EDIT 1

Unless you know exactly about the risk of both processes, don't do it!
This video gives a nice impression of how violently hydrogen and chlorine react upon irradiation! Note that it has nothing to do with the laser involved. A flashlight would give the same dramatic effect! 


EDIT 2

The answer above, giving practical advices on how to get $\ce{HCl}$ and $\ce{NaOH}$ back apparently suggests that you can not simply revert the neutralisation reaction. 

The neutralisation is irreversible.

In order to find out why this is the case, you might want to have a look at thermodynamics of this exothermic reaction, particularly at the entropy changes.