Determine the amount of free run wine juice drawn from your primary fermenter. Add an equal volume of water to the primary fermenter (Example: if you drew 10 gallons of free run wine, add back 10 gallons of water to the primary fermenter).
Also add (per gallon of water):
Keep the fermenter at 70-80 degrees to restart fermentation.
Break the cap and stir twice daily for 5-7 days.
When the specific gravity has fallen to 1.020-1.010, siphon the wine to secondary fermenters (carboys) and smaller top-off vessels, and proceed as for first run wine.
After bottling, this wine will age faster, and therefore may be enjoyed sooner than the first wine. Yield will be 50% (or ½) of the first-run wine.