Oh, you want me to tell you how to do it.
I actually have personally been through this problem, myself. A number of years ago, my wife's uncle passed away. And when going through his personal effects, they found two boxes of cigars in a Ziploc bag. One was 10 Macanudo Maduros, and the other was 10 Partagas Churchills. They had been sittinging in his closet for about 25 years. One would think these would be well-aged, vintage smokes, but they were as dry as a bone.
So I had a well seasoned humidor stabalized at 70%, and I placed the older cigars into the humidor, leaving them in the cellophane. Some would think that taking off the cello and raising the humidity would humidify them faster. Well, it will, but the result probably won't be what you want. The filler will generally humidify faster than the binder or wrapper, causing your cigars to split.
Slow humidification is the key. The slower the better. If you have a humidor running at 65% or so, it might be better.
Now for the end of the dry cigar story...
I tried one at 6 months. It was harsh and hot. I tried another after a year. It was greatly improved. I tried another after 2 years and they became really decent cigars. Patience is the key. It might take two years to sufficiently humidify them to render them smokable.