if you no how to get there skip to paragraph 2
you have to beat ghetis at ns castle after pokemon leuge (first time round) then you go from Nimbassa across the bridge where you couldnt go before (near where you catch zoroak).
Then you go to a building between black city/white forest and the bridge where you can talk to a man who lets you poketransfer
If you new that part you then need another ds with pokemon ss/hh/pt/d/p go on ds download play then ovulasly download pokemon black/white
Then it lets you choose 6 pokemon considering they cant know moves that are different in black and white (i think rock climb is one)
.you cant take items
Then you play a mini game on the ds download ds where there are loads of bushes and a sling shot thing with pokeballs in it you fire at the pokemon your transfering if you catch 1 you get points and it gets transfered
.there is only a certain amount of time
if you run out of time you can only transfer the ones you caught
its not easy to catch them though they hide in bushes and appear every so often
ones you dont catch return to your old game
you then get a final option to transfer the ones you caught because they cant be returned
the pokemon u do transfer should appear in your box of black or whit