charging a ball

you can charge the body  by two ways

1- by conduction

2- by induction.

by induction process you touch any uncharged body  with negatively charged body, due to additive property of the charges, the uncharged body will get negatively charged.

second process is the most intersting one, here one can charge the  uncharged by, without touching it. you take the positvely charged rod near to the huge  given ball,  the charges of the  huge given ball gets polarised, negative charges get accumulated at the surface near to the   positive charged rod and positive charges get accumelated  at the other end  of the sphere. Now get connect the positive end of the sphere with the ground, finally sphere is left with the negative charges, now remove the rod from the sphere, the negativel charges get distributed equally in all directions, so we get the negative charged heavy sphere now.