If you're using the latest firmware you shouldn't need to patch it. Just run the setup program, select where you want to install (whatever drive your N-Card is).
There's are lots of checkboxes for different types of carts on the right of the install window. Make sure you select the SuperCard one (I think it says something about transflash or slot 1 in brackets). You can deselect all the other boxes. It'll install the .nds file. You will get an error message when you start it up, but it should still work fine.