Remove outer leaves from cabbage. Cut cabbage in quarters and remove the tough inner core. Slice across sections into 1/2-inch slices. Put into a colander, add salt, and mix well. Place over a bowl and let drain, covered, until wilted, about 2 hours.
In a large bowl combine the vinegar and sugar and stir to dissolve. Add the chili paste, ginger, garlic, and scallions and stir. Rinse the salt off the cabbage with a couple of changes of water. Dry well and add to the vinegar mixture; stir well to combine. Put into a sterilized glass jar and pack the cabbage down; add enough water to cover. Close the jar and refrigerate for at least 4 hours. This is spicy and gets spicier the longer it sits - add or subtract chili paste to your taste.