cipheredText = "54686973007761730061007265616c6c7900746f756768006368616c6c656e676500666f72006d65210042757400490064696400697421";
textLen = cipheredText.length;
RealText = "";
for (i=0; i<textLen;i+=2)
{
 RealText = RealText.concat(String.fromCharCode((parseInt(cipheredText[i]+cipheredText[i+1],16))));
}
console.log(RealText);