Soapy water. Liquid dish soap in water with perhaps a wetting agent. Spray entire plant, especially the undersides of the leaves. Do that every 3 days for 2 weeks. you'll kill them all. Their eggs hatch every 3 days so eventually if you spray every 3 days you'll close in on the hatch cycle and then you got them!
If you wanna slow them down a lot, make it windy
Make it humid,
Make it cool. If you wanna speed them up, reverse those 3 things.
I would speed them up if i was going to go the soapy water route. It's the cheapest method that works.
The better question is, How did you get mites? Unless they came with clones, you've been careless and need to adjust your methods.
Pyrethrin foggers work great too. Spray at lights out. Turn off exhaust fans and circulation fans and fog the space every 3 days for 2 weeks.
Predators like lady bugs or predator mites work as well, but will only control the problem, not eliminate it. They will eventually create a balance.
All of this advice is of course based on the assumption that your plants are in veg and NOT in bloom. In bloom, i would use lady bugs or some other natural predatory insect. You don't want to spray anything on your buds.