Step 1: Go to the official MyEtherWallet website. Then click Send Ether & Tokens.
Step 2: In the field How would you like to access your wallet? choose Private Key as this is usually easier (Keystore File (UTC / JSON, as well as the other options listed, can also be chosen depending on the wallet you are accessing).
Step 3: Select your wallet file, click Unlock and log in to your MEW account.
Step 4: Enter the deposit address from your COBINHOOD Exchange account into the To Address field in MEW.