You can order the boards from OSH Park here:
OSH Park NESRGB JTAG Adapter Board
You will need one of these ribbon sockets:
10-pin Ribbon Socket
And a row of male pin headers like these:
6-pin square posts
Now that will at least get you started if you've got experience soldering. I went a step further and used a row of round slender pin headers, and then soldered the jtag wires to a corresponding row of female IC headers to slip onto those pins (as you can see in the internal image of my adapter port mod). This makes it so I can disconnect the wires from the adapter port without having to de-solder anything.
Now if you prefer not modding the plastic housing of your NES, you can simply use the square-pin adapter assembly I linked to and hook it into the jtag holes of the NESRGB board directly whenever you need to flash the firmware. Details on the NESRGB board's jtag interface are shown below in the stripped wire method of updating the Firmware:
Stripped wire method: You'll need to strip the ribbon cable that came with your Altera Blaster down to six individual wires. The red coating on the first wire corresponds to pin #1 on the Altera Blaster, and each wire after that corresponds to the next pin (i.e. the 2nd wire goes to pin #2, the 3rd wire goes to pin #3, and so on). The wires you want are 1, 2, 3, 4, 5, and 9. These will be hooked into the 6 terminal holes on the NESRGB board as indicated below:
Wire #4 goes into the "3V3" terminal.
Wire #2 goes into the "GND" terminal.
Wire #3 goes into the "TDO" terminal.
Wire #1 goes into the "TCK" terminal.
Wire #9 goes into the "TDI" terminal.
Wire #5 goes into the "TMS" terminal.
Make absolutely certain you have the correct wires hooked into the correct terminals. I leave it to you to decide if you want to solder them or make a temporary interface (which is how I handled it). For reference, below is the Blaster pinout diagram:
Once you have everything hooked up, power on the Nintendo and plug the USB cord-side of the Altera Blaster into your PC. Then run the Quartus II 13.1 Programmer and follow the steps below:
If everything was done properly, you should see the progress bar fill with green as the programmer updates the NESRGB board. Wait until it finishes, then close the program (don't bother saving when prompted), turn the Nintendo's power off, and unhook the Altera from your PC and Nintendo.