You first must make sure that the gym leader is in the gym, because in some games you have to locate the gym leaders first. After that, you may have to get through a puzzle in the pokemon gym to get to the gym leader at the end of the puzzle. After that, you will battle the gym leader, and if all of her Pokemon faint, then you will probably be given a gym badge.
beat him with your pokemon!
You beat all of her Pokemon. You beat all of her Pokemon.
the best way to beat the 7th gym leader is with a fire type Pokemon
beat the gym leader
you beat the gym leader
Beat the GYM LEADER [=
just beat the fourth gym leader
Go to Mawille(eletric gym town) and there will be a gym leader... there is no gym leader
You kill the Gym Leader's Pokemon with your Tepig.
beat gym leader
Water pokemon
you beat the gym leader