How do I enter Extralink so I can expand Black City/White Forest?
I'm going to use an example to explain, and for sake of example, say you're playing White, and want to visit a friend's Black City.
-Boot up both files, turn on C-Gear.
-On Black, go to Black City.
-On White, doesn't matter where you are.
-Go to Wireless, and press 'ENTRALINK'
-You'll see an old man, a tv screen, and you should be in a grassy field of sorts.
-Go to any of the bridges, and the Touch Screen should say something along of the lines of "Searching for a friends world."
-Once the games connect, cross through the barrier to the other side, and press where Black City is on the map that will appear on the Touch Screen, you'll teleport there.
From there, just talk to everyone in Black City, and offer to take them back to your White Forest.
Hope I helped =)