I believe that he's not sure what he should do.
Typically with capacitors you can up the voltage without compromising the circuit - changing the value is a different issue. I would suggest replacing the electrolytic capacitors with Wima because the capacitors you want to replace are in the signal path. I'll go out on a limb here but I'd guess that the caps you're replacing are radial so the spacing can be an issue with the Wima capacitors as the ones stocked by Mouser generally have short legs.