Inducing An Electric Charge

There are several methods of inducing an electric charge on a surface. The simplest is to comb your hair with a plastic comb. Electrons will be transferred from your hair to the comb - it will become negatively charged and your hair, having lost electrons, will become positively charged. This is charging by friction.
You could shine light onto a metal surface. If the frequency of the light is high enough, the surface will lose electrons via the photoelectric effect, leaving it with a positive charge.
Once you have a charge body, you can charge other, conducting bodies by induction. Bring you charged body close to the conducting body, and it will repel like charges and attract unlike charges, though in practice, only electrons -  negatively charged - are free to move. With the charged body close, earth the body being charged. Electrons will flow one way or the other to give the body a charge. Then Remove the earth wire.

Or you can simply bring your charged object close to conducting surfaces in contact, allowing charge to flow one one body to the other. Then remove the point of contact and both bodies will be oppositely charged,