I heard the walkthroughs from youtube but you can't
You cannot re-battle the Gym Leaders in Pokémon Black and White.
You can rematch all 16 gym leaders at the Fighting Dojo near the Saffron Gym, you may have a rematch against the gym leaders only when you got their Poke-gear No., while they are away from the gym at a specific time each week also the rematch is in a specific time (ex. Whitney is missing from the gym any day on 12:00-16:00, go to the Goldenrod Dept. Store 6th floor and get her number, her rematch call is on Saturday Afternoon )
On eather game, sadly, you can't. But on Diamond, Pearl, Platinum, Heartgold and Soulsilver you can...
go to serebii.com it tells how
Well There is no way to rematch the gym leaders unless if you hack it!
You cannot.
Hackless, NO!
You cannot.
I heard the walkthroughs from youtube but you can't
You can't rematch them unless you start again
You cannot re-battle the Gym Leaders in Pokémon Black and White.
You can rematch all 16 gym leaders at the Fighting Dojo near the Saffron Gym, you may have a rematch against the gym leaders only when you got their Poke-gear No., while they are away from the gym at a specific time each week also the rematch is in a specific time (ex. Whitney is missing from the gym any day on 12:00-16:00, go to the Goldenrod Dept. Store 6th floor and get her number, her rematch call is on Saturday Afternoon )
You cannot rematch just any trainer, there are only certain trainers that you can re-battle such as the 4 Elite 4 trainers as well as Alder. Additionally you can rematch the trainers at the Big Stadium and the Small Court in Nimbasa City, you can also rematch Cheren in Victory Road, Bianca in Professor Juniper's lab, Cynthia in her Villa in Undella Town, Morimoto in the Game Freak building in Castelia City and the Royal Unova trainers.
On eather game, sadly, you can't. But on Diamond, Pearl, Platinum, Heartgold and Soulsilver you can...
america
go to serebii.com it tells how