This article is from "The Pipeline; The Offical Journal Of The Hard Pipe Swingers Coalition."
Lesson 1 - Sandstone (Ethics 102)
We begin with sandstone for two reasons. First, just as it is easy for a rock gymnast to take a Hilti to a sandstone trad line, it is also easy to remove the litter in this medium compared to other rock types. Second, because of this fact and the fact that gumbies usually avoid granite, sandstone crags are desecrated most often.
Begin by either leading the route on gear or setting a top rope in order to demonstrate that the bolts are unnecessary. Upon lowering (or ascending), remove the hangars from the bolts. Partially thread the nuts back onto the bolt in such a way that the nut is on enough, but not too much, to allow a crowbar to fit between it and the rock. Pry the bolt hard with the crowbar. Next, tap the bolt with a hammer or smack the hell out of it if needed. Tighten the nut and more of the bolt shaft should emerge from the rock. Repeat the preceding prying, hammering and tightening steps until either the damn bolt is removed or enough of the shaft, so you can can hack saw at least 1/4" more of it than was originally exposed. Tap the remaining shaft at least 1/4" back into the hole using a nail setter. Using a water proof epoxy and generous amount of local sand mixture, neatly and evenly cover the scar.
Sometimes, it is possible to simply turn out the bolt. If this is possible, remove the bolt and proceed to covering the scar.
Your reward is the gratification that you did more of a clean-up and you love the rock more than the pro-bolt, gumby-ridden Access Fund.