Okay, I'll tell you: First, go downstairs from a Pokemon Center. Then, you might receive the Pal Pad. But if you've owned it before, open it up and check <YOUR NAME HERE>'s FRIEND CODE. Then, give that to me. And at the same time, register my FC by pressing REGISTER FRIEND CODE. Type a name to define me in the game. Any name's good. Then, type the FC. Afterwards, press YES. Then...when we're both online, go to the Wi-Fi Club, located in the basement of the Pokemon Center (go downstairs). (Talk to the lady in the middle!) Then, press YES, much like how you'd do it when you enter the GTS. Then, it's better to press X to disable voice chat, because most people don't like it turned on. Afterwards, press the computer, choose TRADE, and wait for me/any other player later on to contact you. Or if not, when you see me/any other player jumping and the bottom screen has my name (at least the name of me in your game) with a symbol depicting two Poke Balls and an arrow, colored in red. Interact with that player and press YES. Then, choose the Pokemon you want to offer. I'll choose mine, and then, we would both say YES to do the trade. Then, once we're done, press EXIT, go to the warp panel, and it's done! You're back at the Pokemon Center.