I don't use Corn, so I'll tell you how to do it with PJ64. Play Super Mario 64 (without using your downloaded save) and a save file will be generated in your save directory. This is your template. Rename your downloaded save to the template and then replace it. When you next go into the emulator, it should have worked (hopefully) Also, even if you have the (U) rom, an (E) save works with it in the case of Super Mario 64 (I tried it)