Well, I don't know about beef but, I have friends who hunt game and they hang it for several days from the rafters of their barn to age it. I know that the steak I buy is "28 days matured" so I guess it's just a case of hanging your side of freshly butchered bovine from the roof of a shed for a month, suitably covered against insects etc.
We've never aged beef before but we've done plenty of pork. My grandfather had a "smoke house" where he hung all the hams and shoulders from hogs on the farm. This was done in the fall when the weather was cooler. They were rubbed down with a mixture of salt, pepper and brown sugar. This is making my mouth water. I hadn't thought about that good country ham in years.