If you are full commercial deconstruction as we are (12 barns and counting this year) you need a crew of 6 minimum (usually 12), the largest "telescopic rotating forklift" you can rent (or own), a minimum 65' crane, and a man lift, and related deconstruction tools-which includes all the modern advance rigging equipment, this gets the architecture documented, down, and shipped-offloaded in 5 to 10 days.

For the "slow and steady" approach, one or two folks can get the job done in about 2 months full time work for the average frame. You will still need the rigging equipment and skill to use it (safety) and average six bucks of scaffold, and/or shear legs for lowering.