<p>I have used cyanoacrylate glue aka superglue to bond PLA. I have created several electronics enclosures. (Definitely the most time-consuming part of the project.)</p>

<p>Now my question is which debonder/solvent can I use to separate the pieces again without destroying the PLA parts?</p>

<p>Wikipedia proposes the following:</p>

<ul>
<li>nitromethane</li>
<li>dimethyl sulfoxide,</li>
<li>methylene chloride,</li>
<li>gamma-Butyrolactone.</li>
</ul>

Acetone
Acetone will dissolve cynoacrylate (superglue) and should weaken it enough to be able to separate the parts.
A readily available cheap source of acetone is nail varnish remover (just make sure you don't buy the acetone free version!).
Give the pieces a soak in nail varnish remover for 10-20 minutes and they should come apart with some prying.
Acetone does not dissolve PLA, so the PLA parts should be undamaged. If you were to try this on ABS parts however, they would begin to dissolve.