It depends on your N64. They come with different video DACs. I think this page lists them all. The MAV-NUS is hardest to solder and that is definitely smaller than MSOP. Here you can see an RGB mod installation on the MAV-NUS. I think that is comparable to the installation process of the HDMI mod. ...

marshallh, how fine do our soldering skills need to be for this mod? I hope there won't be pins smaller than on an MSOP chip.