ender12

Real quick, how would I modify the PID of a pokemon in a gen 2 save (since EC didn't exist yet)? Trying to make a shiny dunsparce from Crystal that will evolve into a dudunsparce once I move it to SV. But I don't see the option to do so. If it's not possible, how would I go about making such a dunsparce? I've searched around quite a bit and can't seem to find a solution. Thanks