Given the fact that the BTCD blockchain seems stuck, it appears to me that the only solution is to sell your BTCD (, transfer your BTC to an exchange that's trading KMD if necessary) and buy KMD. There might be a slight loss (or gain) if the prices of BTCD and KMD do not match the current conversion rate (which I don't know) or if KMD shoots up (or down) between the time you sell BTCD and the time you buy KMD.