How to convert a string with some ASCII codes in it, back to a string with special characters?

Basically I have these strings

var String1 = 'Concepciu00f3n';
var String2 = 'u00d1eembucu00fa';

I want to convert them back so that they will look like this:

var String1 = 'Concepción';
var String2 = 'Ñeembucú';

I’ve been searching a lot but I haven’t found a solution in js yet