Hey, if your TV has an AV out ( commonly called Monitor Out ) you can run double sided RCA cables (the yellow,red and white ones) from the AV out to the EasyCap and plug your N64 into the tv as you normally would. What this does is outputs whatever is on your screen to your EasyCap. Most modern TV's will have an AV out

Once youve done that check this video to get the best settings for your EasyCap -
http://www.youtube.com/v/OYqD7TF-5Y8&rel=0