Maintenance and cleaning instructions?

[Dastari Creel]

I just purchased a 7800 with 24 games (mostly 2600 style) that he's had in storage for some time. All the games are filthy. I'm familiar with cleaning NES games which I've been collecting for years but I can't find a screw on the Atari cartridges. How do I open up the cartridge to get at the board?

 

Also, I was a little disappointed to find that the 7800 has no dust cover over its cartridge connector. I'd like to give the whole game system a thorough cleaning. Is there any kind of cleaning tutorial for cleaning the system? Is it relatively easy to take apart and put back together again? Are there decent diagrams and/or pictures on this process? I definitely want to clean the connector out but I'll probably take some canned air and blow out the insides as well. This thing is really dirty. I'd love to get your cleaning advice.