If you know what beadlocks are, then odd are you've found yourself in a situation to need them. Off-roaders often use extremely low tire air pressures for increased traction, which has a predictably negative effect on the tires' ability to stay on the rims. Beadlocks mechanically clamp the rim to the tire, which keeps it from becoming dislodged when the going gets tough.
Beadlocks come in two parts; the inner flange sits inside of the tire and captures the tyre's inner bead. The outer flange sits on the outside of the tyre's flange, and a series of bolts connects the two flanges to clamp the tire. There are three main concerns: ease of manufacture, tire sealing and performance on the trail.
Purchasing a Kit
Yes, you could take the route of your father's father and make your own beadlock kit, but it isn't worth it. Not only will you go through huge amounts of very expensive steel plate to make the rings, anything short of precision machining will result in leaky, mismatched beadlocks that don't perform as expected. Most weld-on beadlock kits are about the same, but make sure to get one made of the strongest steel you can find. Most kits are shipped with Grade 5 bolts, which should be sufficient.
Prepping the Rim
The first thing you'll have to do is cut the existing outside flange off of your rim, which can be a lot easier than you might think. True, you could just mark a line, take a grinder to it and hope for the best, but there is a simpler and more effective solution. First, raise the back of your truck off the ground, secure the axle with some sizeable blocks and chock the front wheels. Do not use jackstands. Bolt your rim onto the raised axle, start the truck and let it idle in first gear to spin the rim; you now have a very effective lathe. The only thing you need do now is to press a carbide cutter to the rim just behind the bead, applying light pressure until it cuts through. Be careful when you get to the end; that scrap metal hoop will spin off pretty quickly.
Securing the Beadlock
From here, you can simply follow the kit's instructions on welding the beadlock onto your rims. In almost every case you'll want to secure it with a series of 1/2-inch welds, making sure to keep the heat down so as not to warp the metal. One thing the kit won't tell you is to braze the joint for strength and sealing, but it's always a good idea. Even very talented welders can leave tiny pinholes, which is a serious problem for air retention.
If you're not familiar with brazing, just think of it as soldering on steroids. You heat the weld with a propane torch to red-hot, and apply the flux-coated brazing rod to the area. The brazing rod will liquefy and flow into any gaps in the weld, hardening inside to form a bulletproof seal.