You can do the intial cross either way (which is nice if you don't know what gender your silver-laced will be!)
All you really want to do is cross the chocolate gene into the silver laced line, so in each generation you should pick a bird that you know has chocolate, and cross it to a silver-laced bird of the opposite gender.
If you cross a chocolate (solid or laced) hen to a silver laced rooster--keep only the sons, because they must carry chocolate, inherited from their mother. If one is chocolate laced and another is solid chocolate--keep the laced one, of course.
If you cross a chocolate-carrying rooster (either one of his parents was chocolate) to a silver laced hen, half of the daughters will be chocolate (solid or laced), so keep one of them--preferrably a laced one, of course. The other half of the daughters will not have chocolate. None of the sons will show chocolate, but half will carry it--you just don't know which half.
If you alternate those two generations, you will eventually have some fairly good chocolate laced silver hens, and can breed them to either their sons or their fathers (black laced silver, carry chocolate but do not show it) to get some roosters that also are chocolate laced.
At that point, you have silver laced chocolates of both genders, which should breed true.