For future reference.
click NuShares
click on 'debug window’
select the ‘console’ tab
type: walletpassphrase “your walletpassphrase here” 600
type: dumpprivkey [your public key here]
What you get is a Base58 encode priv key. So all you need to do is (using javascript notation):
var g=Base58.decode(‘thatdumpedprivedkey’);
var prep= Crypto.util.bytesToHex(g);
var privatekey=prep.slice(2, 66); // remove prefix and compression flag+checksum
then, go to https://wallet.peercointalk.org/ -> Wallet Details and paste the privatekey and hit view details