Five screw NES games

I bought a NES Golf from a local gaming store, and saw that it had five screws. But, unlike the security screws we seen on SNES games, these were shaped kind of like pokeballs, with the circle being an inward groove. If I wanted to open that cart up, what would I use?

You can use a flathead screwdriver to open them.

Edit: I'll be damned. You're right. I thought the lines were protruding outward. Thanks.

And dash it! It doesn't have the famicom cart adapter. Is there one that's commercially available or must I go play Japanese games through some unsavory means?

You can wait until December 10th, and then purchase a Retron 5. It's going to have a built-in Famicom slot, so Famicom games will work with it from the word go.

There are commercially available 60-to-72 pin adapters readily available all over the place, and in general, you won't have a problem using them as long as you make sure to take note of the direction that the game faces in an NES. I believe that Famicom games will face downward when plugged in "properly" on a front-loading NES.

Depending on where you got the game though, you might have to disable the 10NES CIC lockout chip, which is very easy to do, and improves the ability of the NES to play games without encountering that flashing red light problem. 

Personally, I think the retron is cool, but I'm all about original hardware whenever possible.