怎樣除去電鍍鎳

first of all
we need to consider whether what is electroplated with nickel

if the substance plated have no reaction with sodium hydroxide (NaOH)
add the substance to dilute NaOH(aq) and nickel(II) hydroxide,
which is insoluble, will be precipitated out
then we may just clean the surface

if the substance plated have no reaction with mineral acid (HCl/H2SO4/HNO3)
add the substance to dilute HCl/H2SO4/HNO3(aq) and nickel(II) salt
which is soluble, will dissolve

other way such as using electrolysis can also be used
we can electrolyze nickel(II) sulphate
using the substance anode and nickel cathode