If you don't have any power tools, I'd do a combination of scoring, breaking, and cutting before filing. A dozen passes with an x-acto knife and some pliers to snap the corner off will do the trick.

Ah! Will do! *salute*

@Kitsch: My local hardware store sells dremels for about 120 bucks, which is a bit steep at this point I think. I've spent a lot of cash on other stuff recently so it will have to wait. :S

Soooo... I think the most viable option right now is to just use a file, as Apeshit suggested.

Thanks guys!

works wonders on stuff like this (more heavy duty materials).  but it works REALLY well so keep good control and don't let the dremel get away from you.

if you go to a decent hardware store that has dremel parts, they should have two or three sizes of this style bit.  its my 'go-to' right now.  love it.

(I gather this belongs in this section of the forum since this is applicable for general knowledge too, my case is concerning the Game Boy but I'm also asking just as general advice.)

So. My latest Game Boy mod was to install a small silver bat switch that can toggle the backlight.
I planned pretty meticulously for it but... in the end I ran into a little drawback.

The drawback in question is that the front PCB doesn't sit well anymore because the switch housing is a tad bit thicker than I first imagined.
But just below where it's caught is a corner of the Game Boy's front PCB which is the upper right corner (when looking into the Game Boy screen).
And I'm sorta thinking if it would be possible to safely just cut that corner out. It doesn't seem to have any wiring across that corner so it should be safe to cut it out right?
And if I'm going to do this, what is a good tool for cutting PCB, I know it's not elastic at all so actually just cutting it out with a pair of wirecutters is definitely not going to work, it will probably crack?
And if anyone thinks this is a stupid idea I won't do it, just asking for right now and future reference.

I searched around for this but didn't really come to any straight forward conclusion.
Thanks in advance.