You'll have to go to the gym and fight with them with your own equal or better Pokemon team.
beat the gym leaders
you can do about anything after you just cant beat the gym leaders again.
In order to beat gym leaders you need a wide variety of Pokemon on your team. For the first gym leader, roark, chimchar's mach punch is a great way to beat him and turtwig and piplup can beat him naturally. For Crasher Wake, later in the game, you can beat him with a croagunk with the ability dry skin. Other than that the other gym leaders should be selfexplanatory and you should always have your Pokemon around the level of the gym leader's.
beat the survivel area gym leaders 56 times and the bald guy gives you mewtwo fainted!
You try and beat the 4 th gym
No You cant
battle gym leaders that's what there there for
You have to go to the Poketch building in Jubilife city. Then you talk to the guy standing next to the front desk after you have beaten the gym leaders. The more gym leaders you beat, the more apps you'll get.
beat all the gym leaders to get the masterball beat all the gym leaders to get the masterball
If you beat all the gym leaders then you can try to beat the Elite Four, or you could go get the National Pokedex. (If you've beaten all the gym leaders, your doing pretty good!)
after you beat the elite four and get national pokedex go to the survival area and you can go in a house and fight 3 different leaders a day
No, however, in Pokemon Platinum, it is possible to rebattle gym leaders at the Survival Area.