I think the previous poster meant to dry them off rather than freshen.
You need to milk till production falls to 3 lbs/day or less. During the process of reducing production to 3 lbs you should eliminate 1 milking a day (cut back to only milking once a day). Once you totally quit milking do not touch the doe's teats at all - no stimulation - if possible. Chances are good that her udder will swell tremendously - don't 'help' her out by milking some out as you'll just stimulate more production. If you notice that the udder looks bright red or if the doe goes off her
feed or
water then you do need to check for mastitis. Chances of getting mastitis are much lower if you slowly decrease milk production. Don't milk her fully out during the once a day milking waiting at least a week after first eliminating the second milking. Stop giving all grain - fewer calories during this time means less milk.
gl!
I dry mine off when production falls below a qt/day. Not worth the effort!