Just put this code to the functions.php file
// Change the RSD currency symbol
/**
* Custom currency and currency symbol
*/
add_filter( 'woocommerce_currencies', 'add_my_currency' );
function add_my_currency( $currencies ) {
$currencies['RSD'] = __( 'Currency name', 'woocommerce' );
return $currencies;
}
add_filter('woocommerce_currency_symbol', 'add_my_currency_symbol', 10, 2);
function add_my_currency_symbol( $currency_symbol, $currency ) {
switch( $currency ) {
case 'RSD': $currency_symbol = 'RSD'; break;
}
return $currency_symbol;
}