"Easier" way to find shiny pokemon in Pokemon Black 2

[C_uggs]

I want to catch a shiny Magnemite in Black 2, I am trying to find one in Virbank Complex. But so far, I didn't have luck.
Is there any easier way to catch a shiny pokemon ? Or this is just pure luck ?

I don´t know if I can still trade pokemon with others, since the game is old.