Pillars themself do not increase accuracy. they are a means to an end. That being freefloating the barrel and relieving stress points. doing this will increase accuracy.

Pillar bedding is quite easy. If you don't have one already get a Brownell's catalog. The sell adjustable pillars. I recomend these because it removes the necessity of milling the pillars to fit. Then all you have to do is drill the stock out to allow the pillars and epoxy them in place.

Glass bedding can accomplish the same thing. Though it is more difficult to hold the action in the proper position.

I like to do both. I relieve the stock around the barrel and action. Then I pillar bed the action in place. This give me a solid base. Then I glass bed the action and the first inch or so of the barrel in front of the action.