Split the cabbage in half and remove the core. Rinse the leaves well under running water. Then trim the leaves into 2 inch (5 cm) strips crosswise through the stems.
Place the trimmed cabbage in a large bowl, cover with the salt, and massage to coat each leaf with salt, paying special attention to the stem sections. Add enough filtered water to fill the bowl and cover the cabbage, and allow to stand for 2 hours, tossing occasionally. The cabbage is ready when the leaves are limp and bend easily without breaking.
Drain the cabbage and rinse it thoroughly, at least 2-3 times. Allow the cabbage to drain completely after rinsing. Rinse and dry the large bowl.
In a small bowl, combine the garlic, ginger, coconut sugar, fish sauce, rice vinegar and gochugaru. Then return the cabbage to the large bowl, and add the daikon and green onions. *You may want to put on gloves at this point.*
Add the gochugaru mixture to the cabbage mixture, and toss to coat, rubbing the spice mixture into each cabbage leaf thoroughly. Then pack the kimchi into a sterilized jar or other airtight container, leaving about 1 inch (2.5 cm) between the kimchi and the lid. Keep the jar at room temperature for 2 days, it should begin to ferment and smell slightly sour. Then open the jar and use a clean spoon to push the kimchi down into the brine and refrigerate. You may want to eat the kimchi now, but it’s best after being refrigerated for at least a week.