Dawn and water, 1:3 ratio on a wet cloth, and wipe them off, then spray them with the soap, and wash again. The mites will drown, stuck in the soap. Give a thorough rinsing - The yellow coming in is a lack of nitrogen.

The dying spotty leaves are probably more due to the mites than the nutes. You've got an infestation, and if you don't kill them all, and catch the eggs now, your done, unsmokable crop if it survives much longer - So get them dead today.

I also use dryer sheets in my pots, keeps the mites away.