After 50 years of doing it the hard way, or not at all, here is a couple tips to help you strip insulation from copper wire, and to recover the brass from plug ends.
Forget knives and expensive wire strippers, unless you really have a lot of wire to strip. For most types of insulation, grab a vegetable peeler, place the wire on a solid surface, push down solidly on the peeler and pull the wire under the peeler.
plug ends: boil the ends in water until they soften enough to pull the brass prongs out with pliers. You must wear gloves in doing this.