Well,just create new ETH address with Etherdelta.It will give you new address with private key.
Then send you eth from old wallet to new,purchase ETHD
Thanks, I finally got it figured. I believe that MetaMask has upgraded how thing is done because EtherDelta creates a MetaMask account which mirrors the one I imported without the private key. And after the transaction is done, there is no export private key to MyEtherWallet. Actually there isn't an option. I could see the balance shows up in MyEtherWallet account automatically.
Problem though, I accidentally brought the wrong token 3 EtherDelta windows opened from links from the tutorials I watched without realizing it, and ended up with MOD token which I didn't even know about 10 minutes ago.
