how do you unlock or get the dual wield pistols in black ops 2? please help?

Just keep using the pistol you want fail wielded In game . Every weapon had weapon xp once you get it all the way it you get dual wield since its one of the last unlockables to pistols

Keep using the pistol in question until you unlock the duel wield attachment

You don't get dual wield pistols,you need to level up one single pistol like KAP-40,B23R,to unlock the Akimbo version of it.