Since the chip is under the black blob, you'll have to work a little more to get it to work, but it's still easy in my opinion.
Just a little outside each of the buttons there is a circle of copper. These circles are where you will need to solder to. Simply use a razor to scrape them down and solder the corresponding wires to them. You'll find that the ground can be soldered to the top right solder point. As for the L and R buttons, simply find the two points on the board that the wires from them are soldered to and solder onto those (but make sure you don't solder to the wire going to the ground!).
Hope this helps! PM me if you have any more questions
EDIT: After posting, I realized that the chip under the black stuff might interfere with this mod working. If you get everything all soldered in and the controller does not work, you might have to use your razor or something to remove the chip and black stuff (i know theres a word for it - brain fart).
This post has been edited by billiam5: Nov 1 2006, 06:10 AM