do i unzip the data file into the sd card first? or just copy it into it. also..after its copied the files, do i delete them from the sd card?

do not extract it. copy it as is. First thing you should do to your SD card is to make a couple folders on it. one called original and one called mods. once in test mode copy the original files you are messing with into the original folder on my flash drive. and then you can replace the files with the modded ones you stored in the mods folder on the SD card.