How do you convert a long action bolt to run .223? Details please.

Can someone point me to a resource which shows how to convert a long action bolt to run .223. I find a mish mash of information but nothing clear and concise including detailed part descriptions/numbers and well documented procedures with pictures. Not even Brownells or PTG were very helpful.

Is this something I should really be doing myself with go/no-go gauges or do most of you take it to a gun smith to check the headspace after you've built your new bolt?

Buy a .223 bolt head for the long action. Boilerup has something like this.

He also has a CDI bottom metal unit that accepts the short action magazines.