Okay, I don't want to try explain it so I'm just linking to the page here.
I don't think any of it is that necessary, until you get to:
>Now we'll turn them over [...]
And it will go on about dismantling or insecting or whatever-you-call-iting the cartridge to see the PC Board. I know nothing about technology, so just read before my head explodes. xD
Hope I helped. :)
Source: Above Link