Buying tokens on Etherdelta is hard enough. Moving them off and into MEW is easy once you understand where to find and export the Metamask private key. Here are the steps.
If you have already purchased your tokens on Etherdelta, you must withdraw them into your Etherdelta account. That is inside the confusing box on the upper left hand side of the Etherdelta screen.
They will then pass into your Metamask wallet (account). I had accidentally deleted mine, not understanding how Etherdelta worked, and a new one was created for me during the withdrawal process. Now they should show up in the token tab of your Metamask extension. If not, there is a plus sign at the bottom of the extension where you can add the contract address, decimals, and ticker symbol, just like you do inside MEW.
Now you can go to the MEW Send Ether & Tokens tab. I would suggest the offline version or use VPN. Inside your Metamask extension, there is a key symbol. Click on that, enter your password and you will be able to click and copy. This is your private key for Metamask. You can enter this into the Myetherwallet.com box for "Private Key" and it will recognize it as a wallet private key and open. They are one and the same. You are now inside Myetherwallet but it is your Metamask account.
You may move around freely and transfer your Metamask tokens wherever your wish. If you wish to transfer your Etherdelta/Metamask tokens into your other Myetherwallet account(s), just populate the address field with your Myetherwallet address and move them. There is a lot more functionality in MEW than there is within Metamask.