Store the cigars somewhere with abundant natural moisture in the atmosphere. Damp or humid places like cellars and greenhouses make ideal environments for exposing dried out cigars to constant, steady levels of humidity. Be sure that the place you choose is room temperature, or only slightly warmer or cooler. Never leave cigars in places that receive direct sunlight or are near any kind of heat source. Crack open or remove the lid of the cigar box and make sure the cigars are evenly distributed inside. Leaving the top of the box open will allow moisture to more easily infiltrate the box and penetrate through to the tobacco inside the cigars.  If the cigars aren’t completely dried out, leaving the lid propped open will be sufficient for allowing moisture to enter the box. For thoroughly desiccated cigars, leave the lid off. A warm, damp towel can be folded and placed beneath the stored cigar box to provide an extra boost of moisture for especially dry cigars. Just be careful to change the towel out frequently, or it might mildew. Leave the cigars in the humid location for a couple weeks to a month. Make sure the cigars are situated where they won’t be knocked over, become wet or be exposed to direct heat or cold. This is the simplest method of rehydrating dry cigars, but also the slowest, as rehydration will occur at a very gradual rate.  Though it takes time, slow rehydration works best, as moisture is returned to the cigars little by little, which keeps the cigars from becoming overhydrated.  Overhydration is essentially irreversible, and can result in deadening the cigar’s flavor, making it difficult to keep lit and even causing mold to grow on the tobacco. Check back on the progress of the cigars regularly. Rotate each cigar a quarter turn inside the box every few days; this will ensure that the entire outer edge of each cigar receives the same amount of moisture so that they hydrate evenly.
Find a suitably humid environment to store the cigars. Leave the cigars inside the box with the lid open. Allow cigars to sit for up to a month. Rotate the cigars every 2-3 days.